U.S. Department of Commerce

Economics and Statistics Administration

U.S. CENSUS BUREAU

Age and Sex Composition: 2010

2010 Census Briefs

By

Lindsay M. Howden

and

Julie A. Meyer

C2010BR-03

Issued May 2011

INTRODUCTION

Focusing on a population’s 

age and sex composition is 

one of the most basic ways to 

understand population change 

over time. Since Census 2000, 

the population has continued 

to grow older, with many 

states reaching a median age 

over 40 years. At the same 

time, increases in the number of men at older ages are 

apparent. Understanding a population’s 

age and sex composition yields insights 

into changing phenomena and highlights 

future social and economic challenges.

This report describes the age and sex 

composition of the United States in 2010. 

It is part of a series that provides an 

overview of the population and housing 

data collected from the 2010 Census. 

It highlights analysis of age and sex at 

the national level, as well as for regions, 

states, and counties and for places with 

populations of 100,000 or more. A comparison with Census 2000 data is also 

provided, showing the changes in age and 

sex composition that have taken place 

over the last 10 years.

This report also provides information 

about how age and sex data were collected in the 2010 Census. The data for 

this report are based on the 2010 Census 

Summary File 1, which is among the 

first 2010 Census data products to be 

released.1

SEX AND AGE QUESTIONS

Data on the sex and age composition of 

the United States and your community are 

derived from the 2010 Census questions 

on sex, age, and date of birth (Figure 1). 

The sex question remains unchanged from 

the previous census. Information on the 

sex of individuals is one of the few items 

obtained in the original 1790 Census and 

in every census since.

As with sex, information on age has been 

collected since 1790. The 2010 Census 

age data were derived from a two-part 

question. The first part asked for the age 

of the person, and the second part asked 

for the date of birth. The question is 

1 The 2010 Census Summary File 1 (SF1) contains data on age, sex, race, Hispanic origin, group 

quarters, relationship, tenure, and households at a 

variety of geographic levels down to the block level. 

For a detailed schedule of 2010 Census products and 

release dates, visit <www.census.gov/population

/www/cen2010/glance/index.html>.

Figure 1.

Reproduction of the Questions on Sex, Age, 

and Date of Birth From the 2010 Census

Source: U.S. Census Bureau, 2010 Census questionnaire.
2 U.S. Census Bureau

designed in two parts in order to 

maximize both the accuracy and 

the number of people responding 

to this item. The age question itself 

is unchanged since Census 2000, 

however, an instruction was added 

to guide respondents to report 

the ages of babies as 0 years old 

if they were less than 1 year old. 

In previous censuses, researchers found that respondents often 

reported their babies’ ages in terms 

of days, weeks, or months, rather 

than in terms of years. This instruction was added to reduce reporting 

problems for babies.

AGE AND SEX COMPOSITION 

According to the 2010 Census, the 

population of the United States on 

April 1, 2010, was 308.7 million 

people, representing a 9.7 percent increase in population since 

2000, when the population was 

281.4 million (Table 1). Growth 

was slower than the 13.2 percent 

increase experienced during the 

previous decade, but similar to the 

growth between 1980 and 1990 

(9.8 percent). Of the 2010 Census 

population, 157.0 million were 

female (50.8 percent) while 151.8 

million were male (49.2 percent). 

Between 2000 and 2010, the male 

population grew at a slightly faster 

rate (9.9 percent) than the female 

population (9.5 percent).

The population grew at a 

faster rate in the older ages 

than in the younger ages. 

The data presented in Table 1 also 

include the distribution of the 

population for selected age categories. In the 2010 Census, the 

number of people under age 18 

was 74.2 million (24.0 percent of 

the total population). The younger 

working-age population, ages 18 

to 44, represented 112.8 million 

persons (36.5 percent). The older 

working-age population, ages 45 to 

64, made up 81.5 million persons 

(26.4 percent). Finally, the 65 and 

over population was 40.3 million 

persons (13.0 percent).

Between 2000 and 2010, the population under the age of 18 grew at 

a rate of 2.6 percent. The growth 

rate was even slower for those 

aged 18 to 44 (0.6 percent). This 

contrasts with the substantially 

faster growth rates seen at older 

ages. The population aged 45 to 

64 grew at a rate of 31.5 percent. 

The large growth in this age group 

is primarily due to the aging of the 

Baby Boom population.2 Finally, the 

population aged 65 and over also 

grew at a faster rate (15.1 percent) 

than the population under age 45.

Another important tool for analyzing the age and sex composition 

of the population is the age-sex 

pyramid (Figure 2). The age-sex 

pyramid shows the number of 

males (on the left) and number of 

females (on the right) by single 

years of age. The 2000 and 2010 

pyramids are superimposed to 

make it easy to study the population at each point in time and 

to assess change. The shape of 

the pyramid can give important 

information about the population’s 

2 The Baby Boom includes people born 

from mid-1946 to 1964. The Baby Boom is 

distinguished by a dramatic increase in birth 

rates following World War II and comprises 

one of the largest generations in U.S. history. 

For more information, see Howard Hogan, 

Deborah Perez, and William Bell, Who (Really) 

Are the First Baby Boomers? Joint Statistical 

Meetings Proceedings, Social Statistics 

Section, Alexandria, VA: American Statistical 

Association, 2008, pp. 1009–16.

Table 1.

Population by Sex and Selected Age Groups: 2000 and 2010

(For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/cen2010/doc/sf1.pdf)

Sex and selected age groups 

2000 2010 Change, 2000 to 2010

Number Percent Number Percent Number Percent 

 Total population . . . . . . . . . . . . . 281,421,906 100.0 308,745,538 100.0 27,323,632 9.7

SEX

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . 138,053,563 49.1 151,781,326 49.2 13,727,763 9.9

Female . . . . . . . . . . . . . . . . . . . . . . . . . 143,368,343 50.9 156,964,212 50.8 13,595,869 9.5

SELECTED AGE GROUPS

Under 18 years . . . . . . . . . . . . . . . . . . 72,293,812 25.7 74,181,467 24.0 1,887,655 2.6

Under 5 years . . . . . . . . . . . . . . . . . 19,175,798 6.8 20,201,362 6.5 1,025,564 5.3

5 to 17 years . . . . . . . . . . . . . . . . . . 53,118,014 18.9 53,980,105 17.5 862,091 1.6

18 to 44 years . . . . . . . . . . . . . . . . . . . 112,183,705 39.9 112,806,642 36.5 622,937 0.6

18 to 24 years . . . . . . . . . . . . . . . . . 27,143,454 9.6 30,672,088 9.9 3,528,634 13.0

25 to 44 years . . . . . . . . . . . . . . . . . 85,040,251 30.2 82,134,554 26.6 –2,905,697 –3.4

45 to 64 years . . . . . . . . . . . . . . . . . . . 61,952,636 22.0 81,489,445 26.4 19,536,809 31.5

65 years and over . . . . . . . . . . . . . . . . 34,991,753 12.4 40,267,984 13.0 5,276,231 15.1

16 years and over . . . . . . . . . . . . . . . . 217,149,127 77.2 243,275,505 78.8 26,126,378 12.0

18 years and over . . . . . . . . . . . . . . . . 209,128,094 74.3 234,564,071 76.0 25,435,977 12.2

21 years and over . . . . . . . . . . . . . . . . 196,899,193 70.0 220,958,853 71.6 24,059,660 12.2

62 years and over . . . . . . . . . . . . . . . . 41,256,029 14.7 49,972,181 16.2 8,716,152 21.1

Sources: U.S. Census Bureau, Census 2000 Summary File 1 and 2010 Census Summary File 1.
U.S. Census Bureau 3

composition. The 2010 Census agesex pyramid is typical of developed 

countries, showing a broad base 

with a middle section of nearly the 

same dimension and then gradually 

tapering off at the oldest ages to a 

point at the top. Between 2000 and 

2010, the population pyramid has 

become more rectangular in shape.

The Baby Boom population in 2010 

is evident in the pyramid as a 

bulge at ages 46 to 64. Consistent 

with this trend, the age group 60 

to 64 was the five-year age group 

with the largest percent increase 

(55.6 percent) followed by the 55 

to 59 age group (46.0 percent) 

(Table 2). The five-year age group 

with the largest percent decrease 

was the population aged 35 to 

39 (11.1 percent decrease). The 

lopsided point at the top of the 

pyramid indicates differences in 

the number of males and females 

at older ages. This is a result of 

differences in mortality for men 

and women, where women tend 

to live longer than men. These 

mortality differences between men 

Figure 2.

Population by Age and Sex: 2000 and 2010

2010

(For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod

/cen2010/doc/sf1.pdf)

Male Female

Age 2000

Sources: U.S. Census Bureau, Census 2000 Summary File 1 and 2010 Census Summary File 1.

Millions

3.0 2.0 1.0 0 1.0 2.0 3.0

0 

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100+
4 U.S. Census Bureau

and women also impact another 

important indicator of population 

composition, the sex ratio.

Faster growth in the male 

population led to increased 

sex ratios. 

The sex ratio is a common measure used to describe the balance 

between males and females in the 

population. It is defined as the 

number of males per 100 females. 

A sex ratio of exactly 100 would 

indicate an equal number of males 

and females, with a sex ratio under 

100 indicating a greater number of 

females. The sex ratio at birth in 

the United States has been around 

105 males for every 100 females, 

however, since mortality at every 

age is generally higher for males, 

the sex ratio naturally declines 

with age. This tendency progresses 

through ages 85 and above where 

there are considerably more surviving women. These trends result in 

more males at younger ages and 

more females at older ages. Sex 

ratios can vary from these patterns for many reasons such as the 

impact of international or domestic migration on a population or 

features of the geographic location 

(for example, the existence of college student housing or military 

facilities).

In 2010, there were 96.7 males 

per 100 females, an increase from 

2000 when the sex ratio was 96.3 

males per 100 females, resulting 

from a greater increase of males 

than females over the decade. 

Looking at five-year age groups 

reveals a noteworthy increase in 

the sex ratios for the population 

aged 60 and older between 2000 

and 2010 (Figure 3). This change 

results from a greater increase in 

the male population relative to 

the female population for these 

age groups. Males aged 60 to 

74 increased by 35.2 percent 

while their female counterparts 

increased by 29.2 percent (Table 2). 

A narrowing of the mortality gap 

between men and women at older 

ages in part accounts for this 

difference.

Population aging led to an 

increased median age.

Changes in the structure of the 

population also impact another 

measure of population composition, median age. The median age 

is the age at the midpoint of the 

population. Half of the population 

is older than the median age and 

Table 2.

Population by Age and Sex: 2000 and 2010

(For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/cen2010/doc/sf1.pdf)

Age

2000 2010 Percent change, 

2000 to 2010

Both sexes Male Female Both sexes Male Female Both sexes Male Female

 All ages . . . . . . . . 281,421,906 138,053,563 143,368,343 308,745,538 151,781,326 156,964,212 9.7 9.9 9.5

Under 5 years . . . . . . .

5 to 9 years . . . . . . . . .

10 to 14 years . . . . . . .

15 to 19 years . . . . . . .

20 to 24 years . . . . . . .

25 to 29 years . . . . . . .

30 to 34 years . . . . . . .

35 to 39 years . . . . . . .

40 to 44 years . . . . . . .

45 to 49 years . . . . . . .

50 to 54 years . . . . . . .

55 to 59 years . . . . . . .

60 to 64 years . . . . . . .

65 to 69 years . . . . . . .

70 to 74 years . . . . . . .

75 to 79 years . . . . . . .

80 to 84 years . . . . . . .

85 to 89 years . . . . . . .

90 to 94 years . . . . . . .

95 to 99 years . . . . . . .

100 years and over . . .

19,175,798 9,810,733 9,365,065 20,201,362 10,319,427 9,881,935 5.3 5.2 5.5

20,549,505 10,523,277 10,026,228 20,348,657 10,389,638 9,959,019 –1.0 –1.3 –0.7

20,528,072 10,520,197 10,007,875 20,677,194 10,579,862 10,097,332 0.7 0.6 0.9

20,219,890 10,391,004 9,828,886 22,040,343 11,303,666 10,736,677 9.0 8.8 9.2

18,964,001 9,687,814 9,276,187 21,585,999 11,014,176 10,571,823 13.8 13.7 14.0

19,381,336 9,798,760 9,582,576 21,101,849 10,635,591 10,466,258 8.9 8.5 9.2

20,510,388 10,321,769 10,188,619 19,962,099 9,996,500 9,965,599 –2.7 –3.2 –2.2

22,706,664 11,318,696 11,387,968 20,179,642 10,042,022 10,137,620 –11.1 –11.3 –11.0

22,441,863 11,129,102 11,312,761 20,890,964 10,393,977 10,496,987 –6.9 –6.6 –7.2

20,092,404 9,889,506 10,202,898 22,708,591 11,209,085 11,499,506 13.0 13.3 12.7

17,585,548 8,607,724 8,977,824 22,298,125 10,933,274 11,364,851 26.8 27.0 26.6

13,469,237 6,508,729 6,960,508 19,664,805 9,523,648 10,141,157 46.0 46.3 45.7

10,805,447 5,136,627 5,668,820 16,817,924 8,077,500 8,740,424 55.6 57.3 54.2

9,533,545 4,400,362 5,133,183 12,435,263 5,852,547 6,582,716 30.4 33.0 28.2

8,857,441 3,902,912 4,954,529 9,278,166 4,243,972 5,034,194 4.7 8.7 1.6

7,415,813 3,044,456 4,371,357 7,317,795 3,182,388 4,135,407 –1.3 4.5 –5.4

4,945,367 1,834,897 3,110,470 5,743,327 2,294,374 3,448,953 16.1 25.0 10.9

2,789,818 876,501 1,913,317 3,620,459 1,273,867 2,346,592 29.8 45.3 22.6

1,112,531 282,325 830,206 1,448,366 424,387 1,023,979 30.2 50.3 23.3

286,784 58,115 228,669 371,244 82,263 288,981 29.5 41.6 26.4

50,454 10,057 40,397 53,364 9,162 44,202 5.8 –8.9 9.4

Median age . . . . . . . . . 35.3 34.0 36.5 37.2 35.8 38.5 (X) (X) (X)

 (X) Not applicable

Sources: U.S. Census Bureau, Census 2000 Summary File 1 and 2010 Census Summary File 1. 
U.S. Census Bureau 5

half of the population is younger. 

The median age is often used to 

describe the “age” of a population. In 2010, the median age 

increased to a new high of 37.2 

years, from 35.3 years in 2000, 

with the proportion of the population at the older ages increasing 

similarly (Figure 4). This indicates 

that the U.S. population is aging. 

Globally, the median age of the 

United States is higher than countries that are less developed, but 

younger than most more-developed 

countries.3 The 1.9 year increase 

3 More-developed regions include all 

regions of Europe, plus Northern America, 

Australia/New Zealand, and Japan. Lessdeveloped regions include all regions 

of Africa, Asia (excluding Japan), Latin 

America, and the Caribbean, plus Melanesia, 

Micronesia, and Polynesia. For more 

information, see Population Division of the 

Department of Economic and Social Affairs 

of the United Nations Secretariat, World 

Population Prospects: The 2008 Revision, 

<http://esa.un.org/unpp>.

between 2000 and 2010 was more 

modest than the 2.4 year increase 

in median age between 1990 and 

2000. The aging of the Baby Boom 

population into older age groups 

is contributing to the increase in 

median age. In the United States, 

other contributors include stable 

birth rates and improving mortality.

DIFFERENCES IN AGE AND 

SEX BY GEOGRAPHY

A major strength of census data 

is its detail available at low levels 

of geography that can highlight 

variation in age and sex across the 

United States. This section compares basic age and sex distributions and selected measures among 

the geographies within regions, 

states, and counties as well as 

places with 100,000 or more 

population.

The Northeast had a higher 

percentage at the older ages, 

while the West had a higher 

percentage at the younger 

ages.

In the four census regions, the 

region with the oldest median age 

was the Northeast (39.2), followed by the Midwest (37.7), the 

South (37.0), and the West (35.6).4

Table 3 shows the variation in the 

distribution of population across 

4 The Northeast region includes 

Connecticut, Maine, Massachusetts, 

New Hampshire, New Jersey, New York, 

Pennsylvania, Rhode Island, and Vermont. 

The Midwest includes Illinois, Indiana, Iowa, 

Kansas, Michigan, Minnesota, Missouri, 

Nebraska, North Dakota, Ohio, South Dakota, 

and Wisconsin. The South includes Alabama, 

Arkansas, Delaware, the District of Columbia, 

Florida, Georgia, Kentucky, Louisiana, 

Maryland, Mississippi, North Carolina, 

Oklahoma, South Carolina, Tennessee, Texas, 

Virginia, and West Virginia. The West includes 

Alaska, Arizona, California, Colorado, Hawaii, 

Idaho, Montana, Nevada, New Mexico, 

Oregon, Utah, Washington, and Wyoming.

Figure 3.

Sex Ratio by Age: 2000 and 2010

Note: Sex ratio is calculated as the number of males per 100 females.

Sources: U.S. Census Bureau, Census 2000 Summary File 1 and 2010 Census Summary File 1. 

(For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod

/cen2010 /doc/sf1.pdf)

25.6

28.1

2010 Census

2000 Census

0

20

40

60

80

100

120

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100+

Age

Ratio
6 U.S. Census Bureau

four age groups (under 18, 18 to 

44, 45 to 64, and 65 and over). 

Comparing the percentages by age 

group shows that the West contains the largest percentages in the 

age groups under 18 and 18 to 44 

(24.9 percent and 37.8 percent, 

respectively), while the Northeast 

contains the largest percentages 

in the age groups 45 to 64 and 65 

and over (27.7 percent and 14.1 

percent, respectively). The differences in distribution of the population across age groups accounts 

for the differences in median age 

across the regions.

All four regions had a sex ratio 

of less than 100, indicating 

more females than males.

The sex ratio also varies across 

regions. The Northeast has the lowest sex ratio (94.5 males per 100 

females), followed by the South 

(96.1), the Midwest (96.8), and the 

West (99.3). All four regions had 

more females than males in their 

populations.

Maine and Vermont surpassed 

West Virginia and Florida as 

the states with the highest 

median age.

More variation in these distributions and measures can be seen 

when looking at state-level comparisons. As expected from the 

regional data, the states with the 

highest median ages are located 

largely in the Northeast, with the 

exception of West Virginia and 

Florida (Table 3 and Figure 5). In 

both 1990 and 2000, West Virginia 

and Florida had the highest median 

age of all states. This trend shifted 

in 2010 due to increases in median 

age between 2000 and 2010 for 

the states of Maine, Vermont, 

and New Hampshire. These three 

states had the largest increases 

in median age between 2000 and 

2010, with an increase of 3.8 

years in Vermont, 4.0 years in New 

Hampshire, and 4.1 years in Maine. 

Maine and Vermont surpassed West 

Virginia and Florida as the states 

with the highest median age. 

There were seven states with a 

median age over 40 years.

The five states with the highest 

median age in 2010 were Maine 

(42.7), Vermont (41.5), West 

Virginia (41.3), New Hampshire 

(41.1), and Florida (40.7). In all, 

there were seven states, the previous five plus Connecticut and 

Pennsylvania, with a median age 

of 40 or higher. This was a shift 

from earlier decades, when all 

states had a median age below 40. 

Despite these shifts in median age, 

however, Florida and West Virginia 

remained the states with the highest percentage of the population 

age 65 and over, 17.3 percent and 

16.0 percent, respectively.

Utah remained the state with 

the lowest median age.

In contrast, the states with the 

lowest median age (excluding the 

District of Columbia) remained the 

same as they were in 2000: Utah 

(29.2), Texas (33.6), Alaska (33.8), 

Figure 4.

Age Distribution and Median Age: 1960 to 2010

Sources: U.S. Census Bureau, 2010 Census Summary File 1, Census 2000 Summary File 1, 1990 Census Summary File 2C, 

1980 Census Summary File 2C, 1970 Census of Population, Vol. 1, Characteristics of the Population, Chapter B, Table 50, and

1960 Census of Population, Vol. 1, Characteristics of the Population, Chapter C, Table 156.

Under 18

37.2

35.3

32.9

30.0

28.1

29.5

18–44 45–64 65+ Median age

1960

1970

1980

1990

2000

2010

(In percent. For information on confidentiality protection, nonsampling error, and definitions, see

www.census.gov/prod/cen2010/doc/sf1.pdf)

24.0 36.5 26.4 13.0

25.7 39.9 22.0 12.4

25.6 43.2 18.6 12.6

28.1 40.9 19.6 11.3

34.3 35.3 20.6 9.8

35.9 34.8 20.3 9.0
U.S. Census Bureau 7

Table 3.

Population by Sex and Selected Age Groups for the United States, Regions, States, and 

Puerto Rico: 2010

(For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/cen2010/doc/sf1.pdf)

Area

Both sexes Male Female

Sex 

ratio

Under 18 years 18 to 44 years 45 to 64 years 65 years and over

Median

Number age

Percent NumberPercent NumberPercent NumberPercent

United States . . . 308,745,538 151,781,326 156,964,212 96.7 74,181,467 24.0 112,806,642 36.5 81,489,445 26.4 40,267,984 13.0 37.2

REGION

Northeast . . . . . . . . 55,317,240 26,869,408 28,447,832 94.5 12,333,192 22.3 19,873,499 35.9 15,305,716 27.7 7,804,833 14.1 39.2

Midwest . . . . . . . . . 66,927,001 32,927,560 33,999,441 96.8 16,128,108 24.1 23,722,312 35.4 18,054,247 27.0 9,022,334 13.5 37.7

South . . . . . . . . . . . 114,555,744 56,134,681 58,421,063 96.1 27,788,757 24.3 42,002,579 36.7 29,870,423 26.1 14,893,985 13.0 37.0

West . . . . . . . . . . . . 71,945,553 35,849,677 36,095,876 99.3 17,931,410 24.9 27,208,252 37.8 18,259,059 25.4 8,546,832 11.9 35.6

STATE

Alabama . . . . . . . . . 4,779,736 2,320,188 2,459,548 94.3 1,132,459 23.7 1,707,598 35.7 1,281,887 26.8 657,792 13.8 37.9

Alaska . . . . . . . . . . . 710,231 369,628 340,603 108.5 187,378 26.4 270,980 38.2 196,935 27.7 54,938 7.7 33.8

Arizona . . . . . . . . . . 6,392,017 3,175,823 3,216,194 98.7 1,629,014 25.5 2,312,398 36.2 1,568,774 24.5 881,831 13.8 35.9

Arkansas . . . . . . . . 2,915,918 1,431,637 1,484,281 96.5 711,475 24.4 1,026,205 35.2 758,257 26.0 419,981 14.4 37.4

California . . . . . . . . 37,253,956 18,517,830 18,736,126 98.8 9,295,040 25.0 14,423,538 38.7 9,288,864 24.9 4,246,514 11.4 35.2

Colorado . . . . . . . . . 5,029,196 2,520,662 2,508,534 100.5 1,225,609 24.4 1,913,620 38.1 1,340,342 26.7 549,625 10.9 36.1

Connecticut . . . . . . 3,574,097 1,739,614 1,834,483 94.8 817,015 22.9 1,231,474 34.5 1,019,049 28.5 506,559 14.2 40.0

Delaware . . . . . . . . 897,934 434,939 462,995 93.9 205,765 22.9 318,409 35.5 244,483 27.2 129,277 14.4 38.8

District of Columbia . 601,723 284,222 317,501 89.5 100,815 16.8 292,419 48.6 139,680 23.2 68,809 11.4 33.8

Florida . . . . . . . . . . 18,801,310 9,189,355 9,611,955 95.6 4,002,091 21.3 6,460,456 34.4 5,079,161 27.0 3,259,602 17.3 40.7

Georgia . . . . . . . . . . 9,687,653 4,729,171 4,958,482 95.4 2,491,552 25.7 3,703,257 38.2 2,460,809 25.4 1,032,035 10.7 35.3

Hawaii . . . . . . . . . . . 1,360,301 681,243 679,058 100.3 303,818 22.3 492,018 36.2 369,327 27.2 195,138 14.3 38.6

Idaho . . . . . . . . . . . 1,567,582 785,324 782,258 100.4 429,072 27.4 554,992 35.4 388,850 24.8 194,668 12.4 34.6

Illinois . . . . . . . . . . . 12,830,632 6,292,276 6,538,356 96.2 3,129,179 24.4 4,748,154 37.0 3,344,086 26.1 1,609,213 12.5 36.6

Indiana . . . . . . . . . . 6,483,802 3,189,737 3,294,065 96.8 1,608,298 24.8 2,318,485 35.8 1,715,911 26.5 841,108 13.0 37.0

Iowa . . . . . . . . . . . . 3,046,355 1,508,319 1,538,036 98.1 727,993 23.9 1,052,998 34.6 812,476 26.7 452,888 14.9 38.1

Kansas . . . . . . . . . . 2,853,118 1,415,408 1,437,710 98.4 726,939 25.5 1,012,552 35.5 737,511 25.8 376,116 13.2 36.0

Kentucky . . . . . . . . . 4,339,367 2,134,952 2,204,415 96.8 1,023,371 23.6 1,555,679 35.9 1,182,090 27.2 578,227 13.3 38.1

Louisiana . . . . . . . . . 4,533,372 2,219,292 2,314,080 95.9 1,118,015 24.7 1,667,563 36.8 1,189,937 26.2 557,857 12.3 35.8

Maine . . . . . . . . . . . 1,328,361 650,056 678,305 95.8 274,533 20.7 432,072 32.5 410,676 30.9 211,080 15.9 42.7

Maryland . . . . . . . . . 5,773,552 2,791,762 2,981,790 93.6 1,352,964 23.4 2,114,974 36.6 1,597,972 27.7 707,642 12.3 38.0

Massachusetts . . . . 6,547,629 3,166,628 3,381,001 93.7 1,418,923 21.7 2,410,178 36.8 1,815,804 27.7 902,724 13.8 39.1

Michigan . . . . . . . . . 9,883,640 4,848,114 5,035,526 96.3 2,344,068 23.7 3,416,012 34.6 2,762,030 27.9 1,361,530 13.8 38.9

Minnesota . . . . . . . . 5,303,925 2,632,132 2,671,793 98.5 1,284,063 24.2 1,899,479 35.8 1,437,262 27.1 683,121 12.9 37.4

Mississippi . . . . . . . 2,967,297 1,441,240 1,526,057 94.4 755,555 25.5 1,067,034 36.0 764,301 25.8 380,407 12.8 36.0

Missouri . . . . . . . . . 5,988,927 2,933,477 3,055,450 96.0 1,425,436 23.8 2,113,347 35.3 1,611,850 26.9 838,294 14.0 37.9

Montana . . . . . . . . . 989,415 496,667 492,748 100.8 223,563 22.6 330,420 33.4 288,690 29.2 146,742 14.8 39.8

Nebraska . . . . . . . . . 1,826,341 906,296 920,045 98.5 459,221 25.1 648,541 35.5 471,902 25.8 246,677 13.5 36.2

Nevada . . . . . . . . . . 2,700,551 1,363,616 1,336,935 102.0 665,008 24.6 1,019,158 37.7 692,026 25.6 324,359 12.0 36.3

New Hampshire . . . . 1,316,470 649,394 667,076 97.3 287,234 21.8 446,764 33.9 404,204 30.7 178,268 13.5 41.1

New Jersey . . . . . . . 8,791,894 4,279,600 4,512,294 94.8 2,065,214 23.5 3,115,326 35.4 2,425,361 27.6 1,185,993 13.5 39.0

New Mexico . . . . . . 2,059,179 1,017,421 1,041,758 97.7 518,672 25.2 719,307 34.9 548,945 26.7 272,255 13.2 36.7

New York . . . . . . . . . 19,378,102 9,377,147 10,000,955 93.8 4,324,929 22.3 7,252,871 37.4 5,182,359 26.7 2,617,943 13.5 38.0

North Carolina . . . . 9,535,483 4,645,492 4,889,991 95.0 2,281,635 23.9 3,512,362 36.8 2,507,407 26.3 1,234,079 12.9 37.4

North Dakota . . . . . 672,591 339,864 332,727 102.1 149,871 22.3 246,767 36.7 178,476 26.5 97,477 14.5 37.0

Ohio . . . . . . . . . . . . . 11,536,504 5,632,156 5,904,348 95.4 2,730,751 23.7 3,989,281 34.6 3,194,457 27.7 1,622,015 14.1 38.8

Oklahoma . . . . . . . . 3,751,351 1,856,977 1,894,374 98.0 929,666 24.8 1,348,878 36.0 966,093 25.8 506,714 13.5 36.2

Oregon . . . . . . . . . . 3,831,074 1,896,002 1,935,072 98.0 866,453 22.6 1,382,447 36.1 1,048,641 27.4 533,533 13.9 38.4

Pennsylvania . . . . . . 12,702,379 6,190,363 6,512,016 95.1 2,792,155 22.0 4,388,169 34.5 3,562,748 28.0 1,959,307 15.4 40.1

Rhode Island . . . . . . 1,052,567 508,400 544,167 93.4 223,956 21.3 383,791 36.5 292,939 27.8 151,881 14.4 39.4

South Carolina . . . . 4,625,364 2,250,101 2,375,263 94.7 1,080,474 23.4 1,669,793 36.1 1,243,223 26.9 631,874 13.7 37.9

South Dakota . . . . . 814,180 407,381 406,799 100.1 202,797 24.9 280,080 34.4 214,722 26.4 116,581 14.3 36.9

Tennessee . . . . . . . 6,346,105 3,093,504 3,252,601 95.1 1,496,001 23.6 2,284,491 36.0 1,712,151 27.0 853,462 13.4 38.0

Texas . . . . . . . . . . . 25,145,561 12,472,280 12,673,281 98.4 6,865,824 27.3 9,644,824 38.4 6,033,027 24.0 2,601,886 10.3 33.6

Utah . . . . . . . . . . . . 2,763,885 1,388,317 1,375,568 100.9 871,027 31.5 1,096,191 39.7 547,205 19.8 249,462 9.0 29.2

Vermont . . . . . . . . . 625,741 308,206 317,535 97.1 129,233 20.7 212,854 34.0 192,576 30.8 91,078 14.6 41.5

Virginia . . . . . . . . . . 8,001,024 3,925,983 4,075,041 96.3 1,853,677 23.2 3,001,446 37.5 2,168,964 27.1 976,937 12.2 37.5

Washington ........ 6,724,540 3,349,707 3,374,833 99.3 1,581,354 23.5 2,492,139 37.1 1,823,370 27.1 827,677 12.3 37.3

West Virginia ....... 1,852,994 913,586 939,408 97.3 387,418 20.9 627,191 33.8 540,981 29.2 297,404 16.0 41.3

Wisconsin . . . . . . . . 5,686,986 2,822,400 2,864,586 98.5 1,339,492 23.6 1,996,616 35.1 1,573,564 27.7 777,314 13.7 38.5

Wyoming . . . . . . . . . 563,626 287,437 276,189 104.1 135,402 24.0 201,044 35.7 157,090 27.9 70,090 12.4 36.8

Puerto Rico . . . . . . 3,725,789 1,785,171 1,940,618 92.0 903,295 24.2 1,351,005 36.3 929,491 24.9 541,998 14.5 36.9

Note: Sex ratio is calculated as the number of males per 100 females.

Source: U.S. Census Bureau, 2010 Census Summary File 1.
8 U.S. Census Bureau

and Idaho (34.6). Among the states, 

Utah had the highest percentage of 

its population under age 18 (31.5 

percent), which contributed to its 

low median age. Utah remained 

the only state with a median age 

under 30. All states experienced 

an increase in median age when 

compared with 2000—a further 

indication of population aging. The 

District of Columbia experienced a 

decrease in median age, going from 

34.6 years to 33.8 years. In the 

District of Columbia, almost half 

(48.6 percent) of the 2010 Census 

population was ages 18 to 44. 

Sex ratios were higher in 

Western states and lower in 

Northeastern states.

Table 3 contains the sex ratio for 

each state. There were ten states 

with more males than females in 

the population, indicated by a sex 

ratio greater than 100. These states 

were concentrated in the West and 

Midwest: Alaska (108.5 males per 

100 females), Wyoming (104.1), 

North Dakota (102.1), Nevada 

(102.0), Utah (100.9), Montana 

(100.8), Colorado (100.5), Idaho 

(100.4), Hawaii (100.3), and South 

Dakota (100.1). In contrast, the 

five states with the lowest sex 

ratios (excluding the District of 

Columbia from the ranking) were 

concentrated in the Northeast and 

South: Rhode Island (93.4 males 

per 100 females), Maryland (93.6), 

Massachusetts (93.7), New York 

(93.8), and Delaware (93.9). The 

District of Columbia had the lowest 

sex ratio, at 89.5 males per 100 

females. 

Counties with lower sex ratios 

were found in Northeastern 

states, while counties with 

higher sex ratios were found 

in Western states.

Data for age and sex were also 

evaluated for every county in the 

MT

AK

NM

OR MN

KS

SD

ND

MO

WA

FL

IL IN

WI NY

PA

MI

OH

IA

ME

MA

CT 

AZ

HI

NV

TX

CA CO

WY

UT

ID

NE

OK

GA

AR

AL

NC

MS

LA

TN

KY VA

SC

WV

RI 

DE 

MD 

DC 

NJ 

Figure 5.

Median Age by State: 2010

VT NH

U.S. median: 37.2

Median age

40.0 or more

37.5 to 39.9

35.0 to 37.4

Less than 35.0

PR

(For information on confidentiality protection, nonsampling error, and definitions, see

www.census.gov/prod/cen2010/doc/sf1.pdf)

Source: U.S. Census Bureau, 2010 Census Summary File 1.
U.S. Census Bureau 9

United States. 5 These sex ratios 

are illustrated in Figure 6, which 

provides a map of sex ratios by 

county. From this map, it is evident that counties in Northeastern 

and Southern states tend to have 

lower sex ratios, while counties 

in Western and Midwestern states 

tend to have higher sex ratios. In 

2010, Alaska was the only state 

where males outnumbered females 

in every county. In 2000, Alaska, 

Hawaii, and Nevada had a greater 

number of males than females in 

every county. In 2010, three states 

had a sex ratio below 100 in every 

county: Delaware, Maine, and 

Rhode Island. Both Delaware and 

Rhode Island had sex ratios that 

were below the national level (96.7) 

in every county.

Compared to 2000, there 

were fewer counties in 2010 

where the female population 

outnumbered the male 

population.

Of the 3,143 total counties in the 

United States, 1,096 of these (34.9 

percent) had a sex ratio that was 

less than the national sex ratio 

of 96.7. In all, there were a total 

of 2,089 counties (66.5 percent) 

with a sex ratio below 100, indicating that the female population 

in the county outnumbered the 

male population. This is a decrease 

from what was seen in 2000, when 

5 The primary legal divisions of most 

states are termed “counties.” In Louisiana, 

these divisions are known as parishes. In 

Alaska, which has no counties, the statistically equivalent entities are census areas, 

city and boroughs (as in Juneau City and 

Borough), a municipality (Anchorage), and 

organized boroughs. Census areas are 

delineated cooperatively for data presentation purposes by the state of Alaska and the 

U.S. Census Bureau. In four states (Maryland, 

Missouri, Nevada, and Virginia), there are one 

or more incorporated places that are independent of any county organization and thus 

constitute primary divisions of their states; 

these incorporated places are known as “independent cities” and are treated as equivalent 

to counties for data presentation purposes. 

The District of Columbia has no primary 

divisions, and the entire area is considered 

equivalent to a county and a state for data 

presentation purposes.

73 percent of counties had a sex 

ratio less than 100.

The county with the highest 

sex ratio was Crowley County, 

Colorado, with a sex ratio of 258.6, 

indicating that there were more 

than twice as many men as women 

in the county. This high sex ratio 

results from the presence of a 

state prison in Crowley County. 

The lowest sex ratio was found in 

Pulaski County, Georgia, with a sex 

ratio of 76.1. This low sex ratio 

is partly due to the presence of a 

state prison for women in Pulaski 

County. The total population of 

each of these counties, however, 

was less than 12,500 people. 

Among counties with at least 

100,000 people, there were three 

counties with a sex ratio greater 

than 110: Kings County, California 

(129.6), Onslow County, North 

Carolina (115.7), and Pinal County, 

Arizona (110.4). In both Kings 

County and Pinal County, the high 

sex ratios are due to the presence 

of multiple correctional facilities 

with majority male populations, 

while Onslow County owes its high 

sex ratio to the presence of a large 

Marine Corps base that houses a 

mostly male population. The lowest 

sex ratios among counties with at 

least 100,000 people were found in 

Hampshire County, Massachusetts 

(88.0), Bronx County, New York 

(88.3), and New York County, New 

York (88.3). In Hampshire County, 

the low sex ratio is influenced by 

the presence of several colleges, 

two of which are women’s colleges.

County-level median ages 

followed patterns seen at the 

state level.

There was also variation at the 

county level in the median age. 

Figure 7 provides a map of median 

age by county for all counties in 

the United States. While median age 

varied significantly among counties, 

patterns emerge that are consistent with findings reported earlier. 

For example, counties in Florida, 

New England, and the Appalachian 

Mountain area tend to have higher 

median ages, along with a band 

of counties in the Great Plains 

and Pacific Northwest. Counties 

with lower median ages are found 

clustered along the United States–

Mexico border and within the states 

of Utah and Alaska.

The number of counties with 

a median age over 40 grew, 

while those with a median age 

less than 30 declined between 

2000 and 2010.

Of the country’s 3,143 counties, 

there were 1,683 counties with 

a median age over 40. This is an 

increase of more than double from 

Census 2000, where 734 counties 

were found to have a median age 

over 40. In contrast, there were 

only 93 counties with a median 

age below 30, compared with 131 

counties in 2000. The county with 

the highest median age was Sumter 

County, Florida (62.7), a county 

with a population of just under 

93,500, which is home to a large, 

age-restricted retirement community. The lowest median age was 

found in the Wade Hampton Census 

Area, Alaska (21.9), a county with a 

population of less than 7,500. 

Among counties with a 

population of at least 100,000, 

the counties with the highest 

median ages were found in 

Florida.

Examining counties with a population of at least 100,000 shows that 

three counties, all in Florida, had 

a median age over 50: Charlotte 

(55.9), Citrus (54.0), and Sarasota 

(52.5). These were also the counties with the highest median 

ages in 2000. Counties with a 

low median age were consistent 

between 2000 and 2010 as well. 

The lowest median ages were 
10 U.S. Census Bureau 0 100 Miles 0 200 Miles 0 100 Miles 

Figure 6. Sex Ratio by County: 2010 (For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/cen2010/doc/sf1.pdf) Note: Sex ratio is calculated as the number of males per 100 females. Source: U.S. Census Bureau, 2010 Census Summary File 1. S
U.S. Census Bureau 11 0 100 Miles 0 200 Miles 0 100 Miles 

Figure 7. Median Age by County: 2010 (For information on confidentiality protection, nonsampling error, and definitions, see www.census.gov/prod/cen2010/doc/sf1.pdf) Source: U.S. Census Bureau, 2010 Census Summary File 1.
12 U.S. Census Bureau

found in Brazos County, Texas 

(24.5), Utah County, Utah (24.6), 

Cache County, Utah (25.5), Onslow 

County, North Carolina (25.7), and 

Clarke County, Georgia (25.9). 

Three of these counties contain 

large universities, which drive the 

low median age in each county. 

Brazos County, Texas, is home to 

Texas A&M University; Utah County, 

Utah, contains Brigham Young 

University; and the University of 

Georgia is located in Clarke County, 

Georgia. As mentioned previously, 

Onslow County, North Carolina, 

is home to a large Marine Corps 

base with a primarily young, male 

population. The presence of this 

base contributes to the low median 

age and high sex ratio in the 

county. With the exception of Cache 

County, Utah, which was below 

100,000 in population in 2000, all 

of these counties were also in the 

lowest five for median age in 2000 

as well.

Among places of 100,000 or 

more population, the places 

with the highest and the 

lowest sex ratio were both 

in Florida.

Table 4 provides a list of the 

ten places (among places with a 

population of 100,000 or more) 

with the highest and lowest sex 

ratio in 2010.6 The highest sex 

ratio was found in Fort Lauderdale, 

Florida (111.8), followed by Tempe, 

Arizona (108.6), and Wichita Falls, 

Texas (107.5). Of the top ten places 

with the highest sex ratio, six are in 

the West, with the remaining four in 

Southern states. As mentioned previously, both Utah and Washington 

were among the states with the 

highest sex ratios, and both states 

contained a place with a sex ratio 

among the top ten places: Salt Lake 

City, Utah, with a sex ratio of 105.3 

6 The 2010 Census showed 282 places in 

the United States with 100,000 or more population. They included 273 incorporated places 

(including 5 consolidated cities) and 9 census 

designated places (CDPs) that were not legally 

incorporated.

and Everett, Washington, with a sex 

ratio of 103.5.

Interestingly, the place with the 

highest sex ratio and the place with 

the lowest sex ratio were found in 

Florida. The highest sex ratio was 

found in Fort Lauderdale, Florida 

(111.8), while the lowest sex ratio 

was found in Pembroke Pines, 

Florida (85.9). All ten of the places 

with the lowest sex ratios were 

found in Southern states. The list 

of the lowest sex ratios included 

several places from the same 

states, with three places each from 

Alabama and North Carolina, and 

two from Florida.

Among places with a 

population of 100,000 or 

more, five of the ten places 

with the highest median ages 

were located in Florida.

The ten places with a population of 

100,000 or more with the highest median ages were located in 

the South and West regions (Table 

5). Scottsdale, Arizona, had the 

highest median age at 45.4 years—

a value 8 years higher than the 

national median age. Of the remaining places with the highest median 

age, five were found in Florida and 

two were in California.

Florida also had two places that 

were included on the list of places 

with the lowest median age: 

Gainesville, Florida (24.9), and 

Tallahassee, Florida (26.1). The 

place with the lowest median age 

was found in Provo, Utah (23.3), 

which is located in the state with 

the lowest median age overall. All 

three of these places were home 

to prominent universities, which 

directly contributed to their low 

median age. Provo, Utah, located in 

Utah County, as mentioned earlier, is the home of Brigham Young 

University. Gainesville, Florida, is the 

home of the University of Florida, 

while Tallahassee, Florida, is home 

Table 4.

Ten Places With the Highest and Lowest Sex Ratio: 2010

(For information on confidentiality protection, nonsampling error, and definitions, 

see www.census.gov/prod/cen2010/doc/sf1.pdf)

Place1 Both sexes Male Female Sex ratio

HIGHEST SEX RATIO

Fort Lauderdale, FL . . . . . . . . . 165,521 87,387 78,134 111.8

Tempe, AZ . . . . . . . . . . . . . . . . 161,719 84,200 77,519 108.6

Wichita Falls, TX . . . . . . . . . . . 104,553 54,172 50,381 107.5

Norfolk, VA . . . . . . . . . . . . . . . . 242,803 125,797 117,006 107.5

Paradise CDP, NV . . . . . . . . . . 223,167 115,508 107,659 107.3

Columbia, SC . . . . . . . . . . . . . 129,272 66,532 62,740 106.0

Salt Lake City, UT . . . . . . . . . . 186,440 95,627 90,813 105.3

Santa Ana, CA . . . . . . . . . . . . . 324,528 165,752 158,776 104.4

Costa Mesa, CA . . . . . . . . . . . 109,960 55,968 53,992 103.7

Everett, WA . . . . . . . . . . . . . . . 103,019 52,392 50,627 103.5

LOWEST SEX RATIO

Pembroke Pines, FL . . . . . . . . 154,750 71,515 83,235 85.9

Jackson, MS . . . . . . . . . . . . . . 173,514 80,615 92,899 86.8

Miami Gardens, FL . . . . . . . . . 107,167 50,121 57,046 87.9

Birmingham, AL . . . . . . . . . . . . 212,237 99,337 112,900 88.0

Shreveport, LA . . . . . . . . . . . . . 199,311 93,354 105,957 88.1

High Point, NC . . . . . . . . . . . . . 104,371 49,002 55,369 88.5

Winston-Salem, NC . . . . . . . . . 229,617 107,878 121,739 88.6

Montgomery, AL . . . . . . . . . . . 205,764 96,687 109,077 88.6

Greensboro, NC............. 269,666 126,793 142,873 88.7

Mobile, AL . . . . . . . . . . . . . . . . 195,111 91,783 103,328 88.8

1

 Places of 100,000 or more total population. The 2010 Census showed 282 places in the United 

States with 100,000 or more population. They included 273 incorporated places (including 5 consolidated 

cities) and 9 census designated places (CDPs) that were not legally incorporated.

Source: U.S. Census Bureau, 2010 Census Summary File 1. 
U.S. Census Bureau 13

to both Florida State University and 

Florida A&M University. In all, nine 

of the ten places on the list of the 

places with the lowest median age 

contain large universities, with the 

remaining place, Killeen, Texas, 

home to a large military base. Three 

places in Texas are on the list of the 

ten lowest median ages.

ADDITIONAL FINDINGS ON 

AGE AND SEX

At what age were there almost 

twice as many women as men?

In the 2010 Census, there were 

approximately twice as many 

women as men at age 89 (361,309 

compared with 176,689, respectively). This point occurs about 

4 years older than it did in 2000, 

and 6 years older than it did in 

1990. This increase is further 

evidence of the narrowing gap in 

mortality between men and women 

occurring at the older ages.

What are age heaping and digit 

preference?

The tendency for respondents to 

report certain ages at the expense 

of other ages is called age heaping. This is also referred to as digit 

preference, which is the preference 

for certain ages, such as those ending in “0” or “5.” Age preference can 

also include preference for a particular age, like 29, 65, 85 or 100. 

This phenomenon varies across 

cultures and is impacted by data 

collection methods. The Census 

Bureau strives to reduce age heaping by collecting both age and 

date of birth information. Overall, 

age heaping did not appear to be 

a concern at the national level in 

Census 2000.7 Early evaluations of 

the 2010 Census data show similar 

results.

7 For more information, see Kirsten West, 

“Did Proxy Respondents Cause Age Heaping 

in Census 2000.” Paper presented at the 

Annual Meeting of the American Statistical 

Association, August 7–11, 2005.

What drove the overall decline 

in the age dependency ratio? 

The age dependency ratio provides 

a very rough approximation of 

economic dependency in a population by dividing the dependent-age 

population (children and older 

adults) by the working-age population. It is often derived as the number of people in the “dependent” 

age categories (under age 18 and 

65 and over) per 100 working-age 

people (18 to 64). This ratio can be 

separated into two parts, the oldage dependency ratio (65 and over 

divided by the working-age population) and the child dependency 

ratio (under-18 population divided 

by the working-age population). 

At the national level, the total age 

dependency ratio declined from 

61.6 in 2000 to 58.9 in 2010, 

indicating that there were 2.7 

fewer “dependent-age” people for 

every 100 working-age people. 

However, this overall decline masks 

the differing trends occurring in 

the younger and older population. 

When evaluating the two dependency ratios separately, the child 

dependency ratio declined by 3.3 

(from 41.5 in 2000 to 38.2 in 2010) 

while the old-age dependency ratio 

increased slightly by 0.6 (20.1 in 

2000 to 20.7 in 2010).

How does the dependency 

ratio differ by state?

Dependency ratios also varied from 

state to state, mirroring trends 

in median age by state that were 

discussed earlier. Figure 8 presents 

dependency ratios for every state, 

decomposing the total dependency 

ratio into its two parts (the old-age 

dependency ratio and the child 

dependency ratio). States are ranked 

according to their total dependency 

ratios. As is evident in Figure 8, 

Utah was the state with the highest 

total dependency ratio, and it also 

had the highest child dependency 

ratio. This is not surprising, given 

Table 5.

Ten Places With the Highest and Lowest Median Age: 2010

(For information on confidentiality protection, nonsampling error, and definitions, 

see www.census.gov/prod/cen2010/doc/sf1.pdf)

Place1 Median age (years)

HIGHEST MEDIAN AGE

Scottsdale, AZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45.4

Clearwater, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.8

Cape Coral, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.4

Fort Lauderdale, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.2

Hialeah, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.2

St. Petersburg, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.6

Thousand Oaks, CA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.5

Urban Honolulu CDP, HI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3

Torrance, CA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3

Centennial City, CO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.1

LOWEST MEDIAN AGE

Provo, UT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.3

Gainesville, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.9

Athens-Clarke County unified government, GA . . . . . . . . . . . . . . . . . . 25.9

Tallahassee, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.1

Columbia, MO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26.8

Killeen, TX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.1

Denton, TX............................................... 27.1

Ann Arbor, MI............................................. 27.8

Laredo, TX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.9

Tempe, AZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28.1

1

 Places of 100,000 or more total population. The 2010 Census showed 282 places in the United States 

with 100,000 or more population. They included 273 incorporated places (including 5 consolidated cities) 

and 9 census designated places (CDPs) that were not legally incorporated.

Source: U.S. Census Bureau, 2010 Census Summary File 1.
14 U.S. Census Bureau

Figure 8.

Age Dependency Ratios by State: 2010

(For information on confidentiality protection, nonsampling error, and definitions, see 

www.census.gov/prod/cen2010/doc/sf1.pdf)

Note: Total bar length represents the total dependency ratio, which is the number of children (ages 0–17) and older adults (ages 65 and over)

per 100 people of working age (ages 18–64) in the state.

Source: U.S. Census Bureau, 2010 Census Summary File 1.

Old-age dependency ratio Child dependency ratio

0 10 20 30 40 50 60 70

District of Columbia

Alaska

Vermont

Colorado

New Hampshire

Virginia

Massachusetts

Maryland

Rhode Island

Washington

New York

California

Georgia

Wyoming

Oregon

Maine

Nevada

Hawaii

North Dakota

North Carolina

Kentucky

Illinois

West Virginia

Louisiana

New Jersey

South Carolina

Tennessee

Connecticut

United States

Minnesota

Wisconsin

Delaware

Pennsylvania

Montana

Alabama

Michigan

Texas

Ohio

Indiana

Missouri

Mississippi

Oklahoma

New Mexico

Florida

Nebraska

Kansas

Iowa

Arkansas

South Dakota

Arizona

Idaho

Utah

Ratio
U.S. Census Bureau 15

that Utah was the state with the 

lowest median age, as mentioned 

previously. The lowest child dependency ratio was found in Vermont, 

a state that also had a high median 

age. Excluding the District of 

Columbia, the state with the lowest 

total dependency ratio was Alaska. 

Alaska was also the state with the 

lowest old-age dependency ratio, 

while the state with the highest oldage dependency ratio was Florida, 

again matching trends in median 

age mentioned previously for these 

states. The District of Columbia had 

the lowest dependency ratio overall.

ABOUT THE 2010 CENSUS

Why was the 2010 Census 

conducted?

The U.S. Constitution mandates 

that a census be taken in the 

United States every 10 years. This 

is required in order to determine 

the number of seats each state 

is to receive in the U.S. House of 

Representatives. Age data are used 

to determine the voting age population (age 18 and older) for use in 

the legislative redistricting process.

Why did the 2010 Census ask 

the questions on age and sex?

The Census Bureau collects data on 

age and sex to support a variety 

of legislative and program requirements. These data are also used to 

aid in allocating funds from federal 

programs, in particular to programs 

targeting specific age groups. For 

example, age data are used to 

calculate the proportion of schoolaged children in each district in 

order to properly allocate funds for 

education.

How are age and sex data 

beneficial?

All levels of government need 

information on age and sex to 

implement and evaluate programs, 

such as the Equal Employment 

Opportunity Act, the Civil Rights 

Act, the Women’s Educational Equity 

Act, the Older Americans Act, the 

Juvenile Justice and Delinquency 

Prevention Act, and the Job Training 

Partnership Act. Age and sex data 

are used by the Department of 

Veterans Affairs, the Department 

of Education, the Department of 

Health and Human Services, and 

the Equal Employment Opportunity 

Commission, among others, to aid 

in planning and development of 

services. 

Other equally important uses for 

census age and sex data are in 

planning adequate schools for 

the school age population and to 

determine funding distributions for 

schools and planning for numerous 

social services such as highways, 

hospitals, health services, and 

services for the older population. 

Census age data are also an important source of information on population aging, such as measurement 

of people eligible for Social Security 

and Medicare benefits. In addition 

to these public uses of census data, 

census data can also be used by 

private organizations. For example, 

census data can help researchers 

studying trends related to mortality 

and population aging or help small 

business owners in planning where 

to best locate their businesses to fit 

the needs of the community.

FOR MORE INFORMATION

For more information on age and 

sex in the United States, visit the 

U.S. Census Bureau’s Internet sites 

at <www.census.gov/population

/www/socdemo/age/> and 

<www.census.gov/population

/www/socdemo/women.html>.

Data on age and sex from the 

2010 Census Summary File 1 provide information at the state level 

and below and are available on 

the Internet at <factfinder2

.census.gov/main.html> and on 

DVD. Information on confidentiality protection, nonsampling error, 

and definitions is available on the 

Census Bureau’s Internet site at 

<www.census.gov/prod/cen2010

/doc/sf1.pdf>.

Information on other population 

and housing topics is presented 

in the 2010 Census Briefs series, 

located on the U.S. Census Bureau’s 

Web site at <www.census.gov

/prod/cen2010/>. This series 

presents information about race, 

Hispanic origin, age, sex, household type, housing tenure, and people who reside in group quarters.

For more information about the 

2010 Census, including data products, call the Customer Services 

Center at 1-800-923-8282. You 

can also visit the Census Bureau’s 

Question and Answer Center at 

<ask.census.gov> to submit your 

questions online.
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