Free shower water usage calculator. Enter your shower length and flow rate to find how many litres and gallons of water each shower uses.
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Enter your shower length in minutes and the shower flow rate in litres per minute. Water used equals minutes multiplied by flow rate, shown in litres and in gallons. Use the flow rate table below if you do not know your showerhead rating.
Water used equals flow rate times shower duration. A 10 minute shower at 9.5 litres per minute uses 95 litres, which is 25.1 gallons, since gallons equal litres divided by 3.785. Both variables matter: halving the time saves as much as halving the flow rate. Your total household consumption is the sum of every fixture, and the shower is often the largest single share.
Older showerheads can flow at 5 to 8 gallons per minute (gpm), which is about 19 to 30 litres per minute. A standard modern showerhead flows at 2.5 gallons per minute (gpm), about 9.5 litres per minute. A low-flow WaterSense showerhead flows at 1.5 to 2.0 gallons per minute (gpm), about 5.7 to 7.6 litres per minute.
Most showers last 8 to 10 minutes. Research cited by water guides puts the average US shower near 15.8 gallons over about 7.8 minutes. A 10 minute shower on a standard 2.5 gallon per minute head uses 25 gallons, while the same shower on a 1.5 gallon per minute head uses 15 gallons.
The comparison table pattern is simple: at 2.5 gallons per minute, a 5 minute shower uses 12.5 gallons, 8 minutes uses 20 gallons and 10 minutes uses 25 gallons. At 2.0 gallons per minute those become 10, 16 and 20 gallons. At 1.5 gallons per minute they become 7.5, 12 and 15 gallons.
A full bath uses about 136 litres, or 36 gallons. A short shower usually beats a bath, but a long high-flow shower can pass a bath quickly: 20 minutes at 2.5 gallons per minute is 50 gallons. If you love long showers, a low-flow head is the single biggest saving.
Hold a bucket under the showerhead for exactly one minute, then measure the litres collected. That is your flow rate in litres per minute. You can also check the gallon per minute rating printed on the showerhead, or time how long it takes to fill a one gallon container.
Practical tips that cut both water and cost: fit a low-flow showerhead, shorten showers by 2 minutes, use the navy shower method to save water while lathering, and fix dripping heads promptly. The savings add up fast: a household of four cutting 2 minutes per shower saves hundreds of litres a week. Less hot water also means less water heating energy, so the saving shows up on two bills.
Multiply minutes by litres per minute. A 10 minute shower at 9.5 litres per minute uses 95 litres.
About 15 to 25 gallons for an 8 to 10 minute shower on a standard showerhead. Low-flow heads bring that down to 12 to 20 gallons.
A showerhead rated at 1.5 to 2.0 gallons per minute, including WaterSense labelled models. Modern designs keep pressure up while using less water.
Run the shower into a bucket for one minute and measure the litres. That figure is your flow rate in litres per minute.
No, temperature does not change the volume, but hotter showers cost more in heating energy.
Usually a short shower. A bath uses about 136 litres, while an 8 minute standard shower uses about 76 litres. A very long shower can use more than a bath.
Shorten your shower, fit a low-flow showerhead, try the navy shower method, and fix leaks. Cutting a 20 minute shower to 10 minutes saves more than most fixture changes.
At 2.5 gallons per minute, a 5 minute shower uses 12.5 gallons, about 47 litres. At 1.5 gallons per minute it uses 7.5 gallons, about 28 litres.