Toilet Calculator Resource

Ripples of water droplet

Know your toilet water consumption footprint by using our calculator. Water conservation is very important to the environment and knowing your consumption could help you make decisions on your next toilet or finding a replacement to an inefficient toilet.

According to the EPA, toilets are the highest consumption of water in households, accounting for 30% of the average home’s water usage. (source)

Toilet Water Consumption Calculator


Find GPF and Manufactured Year

These are listed in the inside of your tank lid, inside of the tank above the water line, or on the backside of the tank. These markings will be in the form of a stamp into the porcelain or inked. If you cannot find your GPF listing, then using the manufactured year can determine the GPF of your toilet.

Toilet Age and GPF

  • Before 1982 – 5 to 7 gpf
  • 1982 to 1992 –  3.5 gpf
  • 1993 to present – 1.6 gpf
  • 2004 to present – 1.28 gpf
  • less 2014 to present – 1.1 gpf

Annual Water Consumption Facts

These calculations assumes 1 person using 5 flushes per day, which is the daily average. We are also using the US average water cost per gallon, which is $0.018 per gallon.

Cost of Water Per Type of Toilet

How we did the math: GPF x 5 (flushes per day)  x 365 (days per year) x $0.018 (cost of water)

  • 1.0 GPF Toilet = $32.85 /yr
  • 1.28 GPF Toilet = $42.04 /yr
  • 1.6 GPF Toilet = $52.56 /yr
  • 3.5 GPF Toilet = $114.97 /yr
  • 6 GPF Toilet = $197.10 /yr

As you can see, switching from one toilet to another could save you lots of money per year.

Gallons of Water Consumed Per Type of Toilet

How we did the math: GPF x 5 (flushes per day)  x 365 (days per year)

  • 1.0 GPF Toilet =  1,925 gallons /yr
  • 1.28 GPF Toilet = 2,336 gallons /yr
  • 1.6 GPF Toilet = 2,920 gallons /yr
  • 3.5 GPF Toilet = 6,387 gallons /yr
  • 6 GPF Toilet = 10,950 gallons /yr

Again, you can see how much water you can save by switching to more efficient toilet. According to

Ways to Save

We recommend a few tricks to save on water consumption. Obviously our first recommendation is switching out your toilet for a more efficient one. Next you can add a plastic bottle of water in your tank, which will reduce the amount of water filling up the tank. We also recommend checking for leaks, as they can cause a major waste of water up to 180 gallons per week.

According to, you can install a dual-flush retrofit kit and save upwards to 54% water savings (source)

We hope you enjoyed our water consumption calculator and hope it will make you aware of potential savings for not only your budget, but the environment.

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