How much water does a shower use?

Multiply flow by time

A 2.5 gallons-per-minute showerhead used for 10 minutes uses about 25 gallons. Two people taking the same shower length doubles the household total.

A lower flow rate changes the result

EPA says standard showerheads use 2.5 gpm, while WaterSense-labeled models use no more than 2.0 gpm and must still meet performance criteria. Actual flow depends on the fixture and pressure.

Measure the fixture you actually have

Catch the shower stream in a one-gallon container for a timed interval, multiply to gallons per minute, and repeat with the shower running normally. This avoids confusing pressure with flow.

Cost boundary: water, sewer, and water-heating prices vary by utility. Water volume is the measured part; your bill requires your local rates.