Water Heater Cost Calculator
Energy and cost to heat your daily hot water.
L
°C
°C
%
$/kWh
How it works
Heat needed (kWh) = litres × 4.186 kJ/kg·°C × temperature rise ÷ 3600, divided by heater efficiency. Electric resistance heaters are close to 95–100% efficient, heat pumps can exceed 300%. Standby tank losses are not included. Example: with the default values, energy per day comes to 7.3 kWh.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.