How it is calculated
The temperature in the formula is how many degrees warmer the water became, not the temperature in the shower. If the heat is not electric, enter your own tariff, or leave heating at zero.
kWh = liters × 4184 × temperature rise / 3 600 000
Where the numbers come from
- Usage — unit in the field: L/min
- Minutes — unit in the field: min
- Heating — unit in the field: °C
- Water — unit in the field: currency units/m³
- Electricity — unit in the field: currency units/kWh
Example
8 L/min for 10 minutes is 80 litres. At a water tariff of 50 currency units per m³, that is 4 currency units for the water alone.
Questions
A water rate per cubic meter?
Yes, currency units per m³. The calculator converts liters itself.
A gas water heater?
Enter the gas price converted per kWh, or leave heating out if you do not have the tariff to hand.
A shower head with an aerator?
Enter the real flow rate if you know it. A nameplate figure of 8 L/min is only an example.