What this shower cost calculator includes
This tool estimates shower cost from three main things: the amount of water used, the cost of that water, and the energy needed to heat it. It works for electric showers and gas-heated showers and lets you split usage across up to eight people.
Why flow rate matters so much
Two showers that both last eight minutes can cost very different amounts if one uses far more water per minute. That is why the calculator asks for shower flow rate, with simple low, standard and high-flow presets plus a custom option.
Why the gas version asks for boiler efficiency
A gas boiler has to burn more energy than the hot water actually delivered into the shower. The efficiency input helps convert the useful hot-water energy into the gas you actually pay for.
Important note
This is an estimate rather than a bill replica. Actual cost varies with incoming cold-water temperature, target shower temperature, exact shower head flow, tariff structure, boiler performance and how your local water company charges for wastewater.