A Day in the Life of a Drop

Worksheet #2

This exercise is designed to show how each member of your family uses water in 

the bathroom. The bathroom is a small room where many of us waste a HUGE

amount of water! Using this worksheet, you will learn to calculate each family 

member’s average daily water use (about how much they use each day) for the 

bathroom sink, the shower, the bathtub and the toilet. Follow the instructions 

below to calculate each person’s average daily water use.

Preparation

1. Prepare one Water Use Table for each day of the week. You will need one sheet for each day 

(and one for each bathroom). Enter the day of the week at the top of the sheet where it 

says “Today is:” and fill in each person’s name across the row called “Family Members.” Post 

today’s table in the bathroom with a pen or pencil and either a timer or clock. (Try to find a 

spot where the sheet will stay relatively dry, but remember that you should never put paper 

on hot things such as heaters, vents, radiators, curling irons, etc.) Once you get the OK from 

your parents about where you’re going to keep the sheet, make sure everyone is aware of 

where the sheet is for each bathroom.

2. Ask each member of your family to record the number of minutes they use the faucet and the 

shower and the number of times they flush the toilet or take a bath. (Note that for the toilet 

and the bathtub, you are recording the actual number of times you flush the toilet or take a 

bath, not the number of minutes you are using them.)

IMPORTANT NOTE FOR ROW D: The cells in Row D are split so you can fill out information 

for more than one bathroom, if you need to. Study the diagram below so you’ll know where 

to put your answers.

452.6

577.6

The top half will be the total 

# of gallons of water used 

by one person for the whole 

week for ONE bathroom.

The lower, right half will be 

for the total # of gallons of 

water used by that person 

for the whole week for ALL 

bathrooms. 

Figure 1

If you only have one bathroom in your home, you can leave the lower, right half of the 

cells in Row D blank. 

EPA 832-F-08-054  May 2008



CALCULATIONS

A. Total # of Minutes or Uses Per Person, Per Fixture, 

Per Day 

Find the total number of minutes or uses for each person for each fixture in the bathroom each 

day by completing the following steps:

For parts A1–4 below, record your final answers in each Water Use Table in the row called “Total # 

of minutes or uses per person, per fixture, per day” in the appropriate column for each fixture.

A1. Add up the number of minutes each person used the faucet each day.

A2. Add up the number of minutes each person used the shower each day.

A3. Add up the number of times each person took a bath each day. 

A4. Add up the number of times each person flushed the toilet each day.

Example: Audrey adds up each of the numbers her mom recorded when she used the faucet on 

Monday. 1.5 + 14 + 4 = 19.5 On the Water Use Table, Audrey records 19.5 in her mom’s faucet 

column in the row called “Total # of minutes or uses per person, per fixture, per day.”

B. Total # Gallons Per Person, Per Fixture, Per Day 

Find the total number of gallons of water each person used for each fixture in the bathroom each 

day by completing the following steps:

For parts B1–4, record your answers in the row of each Water Use Table called “Total # gallons per 

person, per fixture, per day” in the column for each fixture. 

B1. Total Faucet Water Use

If you do not have a high-efficiency faucet, multiply each person’s total number of minutes of 

use for the sink faucet (Answer to A1) by the number 2.2 (which equals the maximum number of 

gallons per minute for an average faucet).

If you have a high-efficiency or WaterSense®-labeled faucet, multiply each person’s total number 

of minutes of use for the faucet (Answer to A1) by 1.5 (the maximum number of gallons per 

minute used by most high-efficiency faucets). This will give you the number of gallons each 

person uses the faucet per day.

Example: First Audrey finds out what kind of faucet she has. She asks her mom to help her and 

learns that she does not have a high-efficiency faucet, so she multiplies 19.5 (her answer to 

part A1, the number of minutes her mom used the faucet on Monday) by 2.2 to find that her 

mom used about 42.9 gallons of water from the faucet on Monday. She records her answer on 

the Water Use Table in the row called “Total # gallons per person, per fixture, per day.” 

If Audrey had a high-efficiency faucet, she would have multiplied by 1.5 to find that her 

mom would have used only 29.3 gallons of water from the faucet for Monday. Wow! What a 

difference! If she had a high-efficiency faucet, Audrey’s mom could have saved more than 131⁄2 

gallons of water just from the faucet in one day! 


B2. Total Shower Water Use

Next you’ll need to make the same calculation for the showerhead. If you have a regular 

showerhead, multiply each person’s total number of minutes of use for the shower (answer to A2) 

by the number 2.5 (average number of gallons per minute used by an average showerhead). 

If you have a high-efficiency shower head, multiply each person’s total number of minutes of use 

for the shower (answer to A2) by the number 1.5 (maximum number of gallons per minute used by 

most high-efficiency showerheads). This will give you the number of gallons each person uses the 

shower per day.

B3. Total Bath Water Use

To find the number of gallons used for baths per day, multiply your answer to A3 for each person 

(total number of baths per day) by 40, the average number of gallons of water used per bath. This 

will give you the number of gallons each person uses in bath water each day. 

B4. Total Toilet Water Use

To find the number of gallons of water each person uses by flushing the toilet you’ll first need to 

complete the following steps. 

1. First, have your parents help you find out how old your toilet is. Most toilets will have a 

stamp in the porcelain that tells you what year it was made. If you can’t find it, you’ll have to 

estimate. 

2. Next, multiply each person’s total number of uses for the toilet for each day (your answers to 

A4 for each person) by the number of gallons of water for a toilet in the same age range as 

yours. Use this guide below to figure out what number to multiply by:

a. If your toilet was made before 1982, multiply your answer to A4 (number of times each 

person used the toilet each day) by 6. 

b. If your toilet was made between 1983 and 1993, multiply the answer to A4 by 3.5. 

c. If your toilet was built after 1994 (or you know that you have a high-efficiency model), 

multiply the answer to A4 by 1.6.

d. If you have a WaterSense-labeled toilet, multiply the answer to A4 by 1.28 

These calculations will result in the total number of gallons used per person by flushing the toilet 

each day.

Example: First Audrey found out how old her toilet is. She and her mom looked to see if they 

could find a stamp with the date on it. There was one! It said 1987. After looking at the chart 

to see how many gallons of water a toilet made in 1987 uses per flush, Audrey knew that she 

needed to multiply her mom’s number of uses for Monday (5) by 3.5. When she made this 

calculation, she found that her mom used 17.5 gallons of water from the toilet on Monday. 


By comparison, if Audrey’s toilet was a WaterSense toilet, her mom would only have used 6.4 

gallons of water! That’s only about 1/3 of the water her older toilet uses! 

C. Total # Gallons Per Person, Per Day 

Once you have all the daily totals for the gallons of water each family member has used from 

each fixture for the day, you’ll need to add them up for each person to get their daily total.

For part C, record your answers in the row of each Water Use Table called “Total # gallons per 

person, per day.”

Example: Audrey found that her mom used 42.9 gallons of water from the faucet, 18 gallons 

from the shower, 0 gallons from the bath and 17.5 gallons from the toilet. When she added them 

up, she found that her mom used 78.4 gallons of water on Monday. 

If Audrey had all high-efficiency fixtures in her home, her mom’s total would have been 53.7, 

which is 24.7 gallons or about 1/3 less water every day! 

D. Total # Gallons Per Person, Per Week 

At the end of the week, add up the number of gallons used by each person for each day. Record 

your answer for each person in the row called “Total # gallons per person, per day.” 

IMPORTANT: If you have more than one bathroom, remember to add the number of gallons for 

each bathroom first, and record that total on each sheet. Then add each bathroom together to get 

your total and record this answer in the lower half of the divided cells in Row D as seen in Figure 1. 

Example 1: After finishing her calculations for #4, Audrey found that her mom used:

577.6

Monday: 78.4 gallons

Tuesday: 76.0 gallons

Wednesday: 82.2 gallons

Thursday: 76.0 gallons

Friday: 81.0 gallons 

Saturday: 88.0 gallons

Sunday: 96.0 gallons

TOTAL: 577.6 gallons


Example 2: If Audrey had two bathrooms in her house, she would have two sets of answers. In 

that case, her calculations would look like this.

Bathroom 1 Bathroom 2

Monday: 66.4 gallons Monday: 12.0 gallons

Tuesday: 56.0 gallons Tuesday: 20.0 gallons

Wednesday: 64.2 gallons Wednesday: 18.0 gallons

Thursday: 61.0 gallons Thursday: 15.0 gallons

Friday: 72.0 gallons Friday: 9.0 gallons

Saturday: 67.0 gallons Saturday: 21.0 gallons

Sunday: 66.0 gallons Sunday: 30.0 gallons

TOTAL: 452.6 gallons TOTAL: 125.0 gallons

These two totals would go in the upper left corner of the sheets for each bathroom. Then Audrey 

would add them together to get the combined total of 577.6, which would go in the lower, right 

half of the answer square in the row called “Total # gallons per person, per week.” 

E. Average # Gallons Per Person Per Day 

Divide the answer to part D (Total gallons per person per week) for each person by 7 (or, if you 

did not conduct the exercise for a full week, divide by the number of days you conducted the 

activity). This number is the average number of gallons each person uses per day. Record your 

answers in the row called “Average # gallons per person per day” in the table.

BONUS: Find out how much water your whole family uses every day! Add up the answers to 

part D (Total # gallons per person per day) for each family member and divide by the number of 

family members who participated. Audrey’s family uses more than 550 gallons of water everyday...

yikes! Looks like it’s time for Audrey’s family to start learning how to use water more efficiently! 

We can all do a better job of using water efficiently. 

Check out the Pledge to Filter out Bad Water Habits and learn how to start 

filtering out your bad water habits today!

To learn more about using water more efficiently, go to 

EPA’s WaterSense Web site where there is a section just for kids! 

www.epa.gov/watersense/kids/index.htm

452.6

577.6

125

577.6

A B