More than 45% of water use in the average American home occurs in the bathroom, with nearly 27% being used by toilets. Fortunately, your household can significantly curb its toilet water usage by regularly checking for and fixing leaks, retrofitting older toilets, or installing a new toilet.
High Efficiency Toilets (HETs)
WaterSense (think EnergyStar, only water), has made choosing a high quality toilet simple with its labeling system. To earn this label, toilets must meet rigorous criteria for performance and must use no more than 1.28 GPF. Only HETs that complete the third-party certification process can earn the WaterSense label.
How much water toilets use per flush
Toilet water use can vary significantly. Older toilets can use 3.5, 5, or even up to 7 gallons of water with every flush. Federal plumbing standards now specify that new toilets can only use up to 1.6 gallons per flush (GPF), and there are high efficiency toilets that use up to 1.28 GPF.
Replacing an older model toilet with a new low-flow (1.6 GPF) or high efficiency toilet (1.28 GPF) can greatly affect your household's total water usage.
Estimated Gallons Used
* American Water Works Association
Not sure about the how much water your toilet uses per flush? Oftentimes, manufacturers stamp their toilet's water usage per flush on the inside of the tank or on the "neck" of the toilet bowl. If you cannot find your toilet's water use stamp, then determining its age is your key to its water use. Federal plumbing standards passed in 1992 required that toilets use no more than 1.6 GPF, so if your toilet was installed prior to 1992, then it likely uses 3.5-7 GPF.