Water Footprint Calculator Methodology

In concepts & definitions, footprints

Our Methodology for Creating the Water Footprint Calculator

Our Water Footprint Calculator provides a snapshot of how a person’s daily activities and routines impact their water use. The results, reported as a water footprint, are meant to be an estimate that can help people better understand how their habits and behaviors contribute to their overall water use.

The calculations used in the Water Footprint Calculator are an estimate. The data is the latest available at the time of creation of the calculator. In some cases, data came from studies that evaluated personal water use based on individual behaviors. In other cases, national data was used to create statistical averages that allowed for calculation of individual water use. The research pointed out that there is a lack of consistent, high-quality water use data collected in this country; results should be viewed with this in mind. The value of the Water Footprint Calculator lies in its ability to help users understand how they use water and how they can use less.

Assumptions Behind the Calculations

  • These types of assessments are usually based on consumptive water use only, i.e., water that is not returned to the original source. In fact, all of the questions are about consumption except the pet food question which uses water withdrawal data because consumption data isn’t available. (This post describes the difference between withdrawals and consumptive water use.)
  • All questions have been included to get people to think about their water use.
  • Average values shown in the spreadsheet results of the calculator are subject to rounding. Values under 1.0 gallon are shown as “0.”
  • Both the English and Spanish versions of our calculator are based on US data and units only. Use the Water Footprint Network’s calculator for international data and metric units.
Download MethodologyFor questions regarding these methods, please email us.