Water heating energy use and cost calculator

Your choice of water heating system should provide you with enough hot water and also maximize efficiency of energy usage saving you money. This calculator can be used to work out the energy consumption of different water heaters.

Electricity Cost Input

Day rate electricity p/kWh
Night rate electricity p/kWh


Input Data

Size of water heater / volume used per day litres
Temperature of water oC
Heater type / condition
HRU fitted
% of night rate electricity used to heat water


Output Data

Actual energy use - kWh per day Cost of electricity per day Cost of electricity per year