Kathryn M. Dresser

National Institute of Standards and Technology 

Weights and Measures Division

Gaithersburg, MD 20899-2600

U.S. Department of Commerce

Carlos M. Gutierrez, Secretary

Technology Administration

Michelle O’Neill, Acting Under Secretary

of Commerce for Technology

National Institute of

Standards and Technology

William A. Jeffrey, Director

NIST SP 1020-1

August 2005

Consumer Package

Labeling Guide:

Selling by Weight
Certain commercial entities, equipment, or materials may be 

identified in this document in order to describe an experimental 

procedure or concept adequately. Such identification is 

not intended to imply recommendation or endorsement by the 

National Institute of Standards and Technology, nor is it 

intended to imply that the entities, materials, or equipment 

are necessarily the best available for the purpose.

National Institute of Standards and Technology Special Publication 1020-1

Natl. Inst. Stand. Technol. Spec. Publ. 1020-1, 18 pages (August 2005)

Available through NIST Weights and Measures Division

100 Bureau Drive STOP 2600

Gaithersburg, MD 20899-2600

Phone: (301) 975-4004 Fax: (301) 926-0647

Internet: www.nist.gov/owm 
1

Introduction

This guide is intended to provide manufacturers, packers, distributors, and

retailers of packaged products with information about the labeling requirements for commodities that are sold by weight in the consumer marketplace.

The information in this guide is based on the Uniform Packaging and

Labeling Regulation contained in NIST Handbook 1301 . NIST develops

Handbook 130 in cooperation with the National Conference on Weights

and Measures, an organization of industry representatives, government officials, and other interested parties. Handbook 130 is adopted and enforced

by many state and local regulatory agencies.

Declaration of Identity

The identity of the product shall appear on the package label and shall not

be misleading or deceptive. When the label appears directly on the package,

the identity of the product shall appear on the principal display panel and

be generally parallel to the base of the package. The principal display panel

is the panel of the package that the manufacturer, packer, or distributor

intends to be displayed at retail. Directions on how to determine the area

of the principal display panel are included later in this guide. The base of

the package shall be determined by how the package is designed to be displayed.

The identity shall be:

z the name specified in, or required by, any federal or state regulation, or 

z the common or usual name, or

z the generic name or other appropriate description, including a statement of function.

For example: "cleaning powder," or "corn chips."

1"Uniform Laws and Regulations in the area of legal metrology and engine fuel quality."
2

Declaration of Responsibility

The name and address of the manufacturer, packer, or distributor shall be

conspicuously displayed on any package that is sold, kept, offered, or

exposed for sale at a location that is different from where it was packed.

The name shall be the actual corporate name or, when not incorporated, the

name under which business is conducted. The address shall include the

street address, city, state, and ZIP code . The street address may be omitted, however, if it is listed in a current city or telephone directory.

Unless it would be misleading, the declaration may be the responsible party's

principal place of business instead of the location where the commodity

was manufactured, packed, or distributed. When the responsible party is

not the manufacturer, the declaration shall include the responsible party's

connection with the package, such as "Manufactured for and packed by" or

"Distributed by."

Declaration of Quantity

All declarations of quantity shall permit price and quantity comparisons. In

general, a declaration of quantity shall be expressed in terms of weight if

the commodity is solid, semisolid, viscous, or a mixture of solid and liquid.

When a product is composed of solids in a liquid packing medium, the declaration of quantity should be in terms of drained weight.

A declaration of net quantity shall appear on the package label and shall be

accurate exclusive of all packaging materials. When the label appears directly on the package, the quantity declaration shall appear in the lower 30 % of

the principal display panel and be generally parallel to the base of the package.

2The country name if outside the United States.

3The country mailing code if outside the United States.
3

Units and Symbols

For metric declarations:

· The metric units required are those of the International System of

Units (SI).

· The units of mass used in an SI quantity declaration shall be in

terms of the kilogram, gram, or milligram. Only the following

words and symbols for SI units shall be used in conjunction with a

weight declaration:

For inch-pound declarations:

· The units of weight used in an inch-pound quantity declaration shall

be in terms of the avoirdupois pound and ounce. Only the following words and abbreviations shall be used in conjunction with a

weight declaration:

Capitalization

SI symbols for weight shall not be capitalized. Inch-pound abbreviations

for weight may appear in both upper and lower case letters.

Use of Punctuation

Periods or other punctuation shall not be used after SI symbols. Periods or

other punctuation should not be used after inch-pound abbreviations.

kilogram kg

gram g

milligram mg

avoirdupois avdp

pound lb

ounce oz

weight wt

drained weight dr wt
4

Use of Spaces

A space should be used between the SI symbol and the number to which it

refers. For example: 250 g not 250g; 1.5 kg not 1.5kg.

Singular Form

SI symbols shall always be written in the singular form. An "s" shall not be

added to a symbol to express the plural of the symbol. Inch-pound abbreviations should also be written in the singular form. For example, "g" is the

symbol for both "gram" and "grams;" "oz" is the abbreviation for both

"ounce" and "ounces."

Prohibited Symbols

Incorrect symbols to use in SI quantity declarations of weight include: Kg,

Kilo, G, gms, gr, and MG.

Incorrect symbols to use in inch-pound quantity declarations of weight

include: # and Pnd.

Use of Units and Symbols

Largest Whole Unit

The quantity declaration shall be in terms of the largest whole unit of

weight, with any remainder expressed in fractions.

For SI declarations:

· The quantity shall not be expressed in mixed units. For example: 3.5 kg

not 3 kg 500 g.

· A weight of less than one gram shall be expressed in milligrams.

· A weight of one gram or more, but less than 1 kilogram, shall be

expressed in grams and decimal fractions of a gram.

· A weight of one kilogram or more shall be expressed in kilograms and

decimal fractions of a kilogram.
5

· A remainder shall be expressed as a decimal fraction of the largest

whole unit (common fractions are not allowed). For example: 1.25 kg

not 1-1/4 kg; 420.2 g not 420-1/5 g.

For inch-pound declarations:

· The quantity may be expressed in mixed units. For example: 2.25 lb

and 2 lb 4 oz are both acceptable.

· A weight of less than one pound shall be expressed in ounces and fractions of an ounce.

· A weight of one pound or more shall be expressed in pounds with any

remainder expressed as either fractions of a pound, or ounces and fractions of an ounce.

· A remainder may be expressed as either a common or decimal fraction

of the pound or ounce. For example: 1.5 lb, 3-1/2 lb, 14.3 oz, and

12-1/4 oz are all acceptable; or,

A remainder may be expressed in the next smaller whole unit with any

further reminder expressed as a common or decimal fraction of the 

smaller unit. For example: 5 lb 4 oz, 1 lb 7.5 oz and 3 lb 2-1/4 oz are 

all acceptable.

Rule of 1000

The selected multiple or submultiple prefixes for SI units shall result in

numerical values between 1 and 1000. This rule requires milligrams to be

used when a weight declaration is less than 1 gram, and kilograms to be used

when a weight declaration is 1000 grams or more. For example: 500 mg, not

0.5 g; 1.4 kg, not 1400 g.

Number of Digits Displayed

SI declarations shall be shown in three digits except where the quantity is

below 100 grams. If below 100 grams, the SI declaration may be shown in

two digits. In either case, any final zero appearing to the right of the 

decimal point need not be shown.
6

Dual Unit Declarations

A quantity declaration shall usually appear in both SI and inch-pound units.

Either unit may appear first in the declaration. For example: 2 kg (4.4 lb)

and 1 lb (453 g) are both acceptable.

Rounding

When declaring equivalent SI and inch-pound quantities on a package,

neither declaration may overstate or understate the actual quantity.

Conversions, the proper use of significant digits, and rounding must be

based on the packer's knowledge of the accuracy of the original measurement and the effect of that accuracy on the converted number. Net content declarations shall not be rounded up to overstate a quantity. When, as

a result of rounding, metric and inch-pound declarations do not exactly

match, the quantity of product in the package shall meet the largest declaration.

Fractions

An SI quantity declaration shall contain only decimal fractions. For example: 1.5 kg, not 1-1/2 kg. An SI declaration shall not be carried out to more

than three places. For example: 2.36, not 2.364287.

An inch-pound quantity declaration may contain either decimal or common

fractions. An inch-pound quantity declaration that contains decimal fractions shall not be carried out to more than three places. In an inch-pound

quantity declaration that contains common fractions, all fractions shall be

reduced to their lowest term. For example: 1/2 , not 2/4 ; 1/8, not 4/32 . In addition, common fractions shall be in terms of halves, quarters, eighths, sixteenths, or thirty-seconds unless there is a firmly established general

consumer usage and trade custom of employing different common

fractions for a particular commodity. For example: 3-3/16 lb, not 

3-1/3 lb; 1-3/8 lb, not 1-2/5 lb; 14-9/16 oz, not 14-4/7 oz.
7

Words Accompanying a Quantity Declaration

Use of Phrase "Net Weight"

A quantity declaration of weight may stand alone, or may include the terms

"net weight," "net mass," or just the word "net." For example: Net Wt.

453 g (1 lb); Net 6 oz (170 g); 200 g (7 oz); and 1 lb (453 g) are all acceptable.

Qualifying Phrases Prohibited

Words or phrases that qualify the quantity declaration shall not appear on

the package. For example: "approximately," "minimum," "when packed,"

"not less than," "at least," "giant," and "full" are prohibited from appearing

near the quantity declaration.

Combination Declarations

When a quantity declaration of weight is not fully informative on its own, it

shall be combined with appropriate declarations of measure, count, or size.

All combination declarations shall be accurate and shall appear on the principal display panel as part of the quantity declaration.

Supplemental Declarations

When appropriate, the required quantity declaration may be supplemented

by one or more additional declarations of weight, measure, count or size.

All supplemental declarations shall be accurate and shall appear somewhere

other than on the principal display panel.

Prominence and Placement

All information required to appear on a consumer package shall be prominently displayed in the English language. When appropriate, information

may also be displayed in additional languages. Any required information

that is hand lettered shall be clear and equal in legibility to printed materials.
8

Principal Display Panel

The area of the principal display panel shall be:

· for rectangular containers, the height times the width (H x W) of the

front of the package, where the front of the package is determined by

how the package is designed to be displayed;

· for cylindrical or nearly cylindrical containers, 40 % of the height times

the circumference [0.4 x (H x C)] of the container;
9

· for other shaped containers, 40 % of the total surface area of the container. However, if the container has an obvious principal display panel

(for example, the face of a triangular package of cheese, or the top of a

can of shoe polish) the area shall be calculated from the shape of that

surface.

Color Contrast

The quantity declaration shall be in a color that contrasts conspicuously with

its background. However, the quantity declaration may be blown, formed,

or molded on a glass or plastic surface if no other label information is presented in a contrasting color.

Free Area

The area surrounding the quantity declaration shall be free of printed information:

· above and below by a space equal to at least the height of the declaration

lettering; and

· to the left and right by a space equal to twice the width of the letter "N"

of the declaration lettering type and style.
10

Style of Type

The quantity declaration shall be in a style of type or lettering that is bold,

clear, and conspicuous when compared to other type, lettering, or graphics

on the package. However, if all the label information is blown, formed, or

molded on a glass or plastic surface, then the quantity declaration may also

be blown, formed, or molded on the surface.

Proportionality

No number or letter shall be more than three times as high as it is wide.

Minimum Height

The height of any letter or number in the quantity declaration shall be at

least that shown in the Table on the following page. When all lowercase letters are used in SI symbols, it is the lowercase "d," or its equivalent in the

print or type, that shall meet the minimum height requirement. No letter

shall be less than 1.6 mm (1/16 in) in height. Other letters and exponents

shall be presented in the same type style, and in proportion to the type size

used.
11

Area of Principal 

Display Panel

Note: The type and size requirements specified in this table do not apply to the “e” mark.

Minimum Height of Numbers and Letters

Minimum Height:

Numbers and Letters

Minimum Height:

Label information blown,

formed, or molded on surface of container

4.8 mm (3/16 in)

4.8 mm (3/16 in) 6.4 mm (1/4 in)

12.7 mm (1/2 in)

6.4 mm (1/4 in) 7.9 mm (5/16 in)

14.3 mm (9/16 in)

3.2 mm (1/8 in)

3.2 mm (1/8 in)

1.6 mm (1/16 in) Less than or equal to

32 cm2 (5 in2)

More than 32 cm2 (5 in2) and less than or equal to 

161 cm2 (25 in2)

More than 161 cm2 (25 in2) and less than or equal to 

645 cm2 (100 in2)

More than 645 cm2 (100 in2) and less than or equal to 

2581 cm2 (140 in2)

More than 2581 cm2 (400 in2)
12

Figure 1: Example of a package labeled to be sold by weight

Manny’s M unchies

A peanut butter and banana spread with crackers

Net Wt. 284 g (10 oz)

 Appears in the lower 30 % of the principal 

display panel

 Is generally parallel to the base of the 

package

 Includes both SI and inch-pound units Has the required amount of free space Uses an appropriate style of type Meets minimum height requirements

 Is prominently display Includes the name and address 

of responsible party

 Includes responsible party’s 

connection with the package

 Appears on principal display panel Is generally parallel to the base of 

the package

 Includes a generic name with 

description

Declaration of Quantity:

Declaration of Responsibility:

Declaration of Identity:

Distributed by

Manny Corp.

456 W. Oak St.

Perplunk, OH

43550

1-800-012-3456

Indgredients

Nutrition 

Information
13

How to use the conversion factors:

(1) Look up the unit that you already have in the left-hand column.(2) Travel along the row for that unit until you reach the column of the unit that you want.(3) The number in the location where the unit that you have and the unit that you want intersect is the conversion

factor.

(4) Multiply the number that corresponds to the unit that you have by the conversion factor. The resulting number

is the equivalent value in the units that you want.

For example: You have a weight of 1.3 pounds that you want to convert to grams. Using the chart, the conversionfactor for going from pounds to grams is 453.592 37. Multiply the number of pounds by 453.592 37 to get the number of grams.

1.3 lb x 453.59237 g/lb = 589.670081 g

Conversion Factors

(underlined figures are exact)

Units Pounds Ounces Milligrams Gram Kilogram1 pound = 1 16 453 592.37 453. 592 37 0.453 592 37

1 ounce = 0.0625 1 28 349.523 125 28 349.523 125 0.28 349 523 1251 milligram = 0.000 002 204 623 0.000 035 273 96 1 0.001 0.000 0011 gram = 0.002 204 623 0.035 273 96 1 000 1 0.0011 kilogram = 2.204 623 35.273 9 1 000 000 1 000 1
14

Labeling Checklist for Weight

Declaration of Identity

 Appears on the principal display panel.

 Is generally parallel to the base of the package.

 Is the name specified in, or required by, federal or state regulation;

the common or usual name; or the generic name or other appropriate description including a statement of function.

Declaration of Responsibility

 Is conspicuously displayed on any package that is sold, kept, offered,

or exposed for sale at a location other than the premises where

it was packed.

 Includes the name and address of the manufacturer, the packer, or

the distributor.

 Uses the actual corporate name or, when not incorporated, the name

under which the business is conducted.

 Includes the city, state (or country), and ZIP code (or mailing code

used in other countries).

 Includes the street address unless this information is listed in a 

current city or telephone directory.

 Uses the address of the responsible party's principal place of business

or the address of the location where the package was manufactured,

packed, or distributed unless such address would be misleading.

 If the responsible party is not the manufacturer, then includes the

party's connection with the package (i.e., "Manufactured for and

packed by," or "Distributed by").
15

Declaration of Quantity

 Appears in the lower 30 % of the principal display panel.

 Appears generally parallel to the base of the package.

 Is prominently displayed in English (multi-lingual information is permitted).

 Is in a color that contrasts conspicuously with its background.

 Has an adequate amount of free area around it.

 Appears in a style of type or lettering is bold, clear, and conspicuous.

 Is of a type or lettering that is proportional.

 Is of a type or lettering that meets the minimum height requirements.

 Generally includes both SI and inch-pound units.

 Uses only approved words, symbols or abbreviations for the SI and

inch-pound units.

 Uses SI symbols that are not capitalized.

 Uses SI symbols and inch-pound abbreviations that are not accompanied by periods or other punctuation marks.

 Uses SI symbols and inch-pound abbreviations in the singular form.

 Is declared in the largest whole unit.

 SI units comply with the Rule of 1000.

 Uses SI declarations that are displayed in 2 or 3 digits.

 Is properly rounded so as to not overstate the quantity.

 Uses SI declarations containing only decimal fractions.

 Does not appear in conjunction with an improper qualifying phrase.

 When necessary, is combined with appropriate additional declarations.
16

Contact Information

National Institute of

Standards and Technology

Weights and Measures Division

100 Bureau Drive, M/S 2600

Gaithersburg, MD 20899-2600

Tel: 301-975-4004

Fax: 301-926-0647

E-mail: TheSI@nist.gov

www.nist.gov/metric

U.S. Federal Trade Commission

600 Pennsylvania Ave, NW

Washington, DC 20580

Tel: 202-326-2222

www.ftc.gov

Handbook 130 is available on the NIST Weights and Measures Division website at:

www.nist.gov/owm; click on "Handbook 130, Uniform Laws and Regulations" under

the "Quick List (popular links)" section.

The Fair Packaging and Labeling Act (FPLA) is available 

· on the FDA website at: www.fda.gov/opacom/laws/fplact.htm; or 

· on the FTC website at: www.ftc.gov/ogc/stat3.htm,

click on "Fair Packaging and Labeling Act 

(80 Stat. 1296, 15 U.S.C. §§ 1451-1461)."

A Food Labeling Guide is available on the FDA website at::

www.cfsan.fda.gov/~dms/flg-toc.html

National Conference on

Weights and Measures

15245 Shady Grove Road, Suite 130

Rockville, MD 20850

Tel: 240-632-9454

Fax: 301-990-9771

E-mail: ncwm@mgmtsol.com

www.ncwm.net

U.S. Food and Drug Administration

5600 Fishers Lane

Rockville, MD 20857

Tel: 1-888-463-6332

www.fda.gov