Older toilets can use more than four times per flush. Is it time to switch yours to a WaterSense labeled high efficiency toilet?

More than 47% of water use in the average American home occurs in the bathroom, with nearly 24% 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 toiletsWaterSense (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 high efficiency toilet (1.28 GPF) can greatly affect your household's total water usage. HET's are widely available at home improvement and plumbing stores, and typically cost about $100-400 plus any installation fees. The estimated payback time for a HET typically ranges from half a year to five years depending on the cost of your toilet and your household's annual water and sewer costs. If purchasing and installing a new toilet is not possible, you may be able to retrofit your older toilet.


Average Flushes
Per Day

Estimated Gallons Used
Per Person Per Year




 5 GPF



 3.5 GPF



 1.6 GPF



1.28 GPF



* 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.

How a toilet works

How a toilet works

Think you might have a toilet leak?

Water leaks account for approximately 12% of all water use in the average American home, and the toilet is one of the most likely places to find them. Find out more about detecting and repairing toilet leaks.

How Much Water Do Toilets Use | Regional Water Providers Consortium


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