Formula and example
How it is calculated
kWh = watts / 1,000 × hours; cost = kWh × electricity price
Worked example
100 W for five hours uses 0.5 kWh. At €0.35/kWh, that costs €0.175 per day of use.
Things to check
- The electricity price is an editable example. Standing charges, national tariffs and subsidy limits are excluded. For regulated appliances, use average power consumption.
- Use one currency consistently. Examples use euros; the calculation works with any currency.