A shower costs money in two separate ways, the water itself, and the energy to heat it, this calculator combines both into a single realistic cost figure per shower, per week, and per year.

How to use this shower cost calculator

1. Enter People in Household, Showers per Person per Week, and Average Duration.
2. Enter your shower’s Flow Rate and the Temperature Rise Needed to heat the water.
3. Select your Currency, Water Price, and Energy Price.
4. Select your Water Heater Efficiency (electric, gas, or heat pump).
5. Read your Annual Shower Cost, Cost per Shower, and Weekly Cost.

What this calculator does

A shower costs money two ways: the water itself (flow rate multiplied by duration, priced per 1,000 gallons) and the energy required to heat that water from cold tap temperature up to a comfortable shower temperature. Heating energy uses water’s specific heat, it takes about 8.34 BTU to raise one gallon by 1°F, which this calculator converts into kWh and prices at your entered electricity or gas rate.

Why water heater type changes the cost

Electric resistance water heaters are highly efficient at converting electricity into heat (around 95%), gas water heaters lose more energy up the flue (around 80% efficient), while heat pump water heaters can exceed 100% efficiency in the traditional sense because they move heat rather than generate it, reflected in a coefficient of performance (COP) around 3.5. This calculator’s Water Heater Efficiency setting accounts for that difference directly.

What this calculator doesn’t include

Sewage charges are excluded since they vary too widely by region and utility to estimate meaningfully here. Actual costs will also depend on your specific water heater’s real-world efficiency and your utility’s exact rate structure, which may include tiered pricing this simplified estimate doesn’t model.

Frequently asked questions