Water Use Calculator

Understanding where and how much water we use is the first step in beginning to conserve. This simple home water check-up will help you track your household consumption, both indoors and outdoors. After calculating your water use patterns, you can begin conserving in ways that work best with your lifestyle.

Enter information into the form below and press the "Calculate" button to calculate your daily, monthly, and yearly water use in gallons. You do not need to answer questions if they don't apply.

For more information, see our Indoor Water Conservation and Outdoor Water Audit pages.


Total number of people in your household. (Required)



How many showers are taken each day in your household?
What is the average length (in minutes) of each shower.
  Enter 6.3 if you are unsure.
What is the flow rate (gallons per minute) of your showerhead?
  Enter 5 for standard showerhead; 2 for low flow.
Total number of baths taken each week by members of your household.
  Assuming 40 gallons/bath.


Number of times each person flushes a toilet in your house per day.
  Enter 4 if you are unsure.
How many gallons does your toilet use per flush?
  Enter 5 if you have a standard toilet; 1.6 if you have a low volume toilet.


How many times each day does each household member use faucets to shave, brush teeth, wash hands and face?
How many minutes does the water run during each use?
  Assuming 3 gallons/minute.


How many times are dishes washed by hand each day?
How many minutes does the water run during each wash?
  Assuming 3 gallons/minute.
If you have a dishwasher, how many times is it used each week?
The average dishwasher uses 15 gallons of water per load; change this number if yours is different.


How many loads of laundry are done by members of your household each week.
The average washing machine uses 55 gallons of water per load; change this number if yours is different.


If you use non-potable irrigation water outdoors, remember that your estimates should include this water as well as domestic water.


How many weeks of the year do you water your lawn?
  4 months = 16 weeks.
How many times is your lawn watered each week?
How many minutes is the lawn watered per watering?
How many gallons is used per minute for lawn watering?
  Enter 15 if you are unsure.


Water is also used outdoors to wash cars, fill pools, rinse outdoor furniture and clean equipment.
Estimate the number of minutes water is used outdoors for purposes other than watering each week.
  Assuming 10 gallons/minute.

Press the Calculate button to compute your overall water use.