The calculator takes you through the house, asking questions about your routines in the laundry room, kitchen, bathroom, and outdoors. For example, you'll be asked whether you use a front-load washer, how many times a week you wash dishes, how long you shower and how often you take baths, and whether you wash your car at home. Then, the calculator will tell you approximately how many gallons of water your household uses each day, week, and year.
Of course, it's only an estimate and doesn't factor in every detail. For example, your household's water use might actually be lower if you've installed water-saving kitchen faucets or dual-flush toilets ... or it could be higher if you or your housemates stand in the shower longer than you reported.
We also think the calculator would be more helpful if it provided a breakdown of gallons per activity rather than just a grand total. (For water use statistics by activity, the American Water Works Association has a helpful chart.) Still, it's an enlightening – and potentially shocking – exercise, and over time you can revisit the calculator to see how changes in your routine have helped reduce your water consumption.
• Save Your Water, from Underwriters Laboratories
(Image: Underwriters Laboratories)