Electricity consumption calculator
Enter the appliance power, daily usage hours and kWh price to get the estimated daily, monthly and annual cost.
Calculation methodology
E (kWh) = (P × t) / 1000 C (€) = E × Pr
P = power (W); t = hours/day; Pr = kWh price.
Worked example
A 2000 W heater used 2 h/day at €0.15/kWh consumes 4 kWh/day and costs €0.60/day, €18/month and €219/year.
Frequently asked questions
Where do I find my appliance power?
On the rating label or specification plate, usually on the back or bottom, in W or kW.
How do I know my kWh price?
On your latest bill, in the 'energy term' section. It varies depending on whether you have a regulated or free-market tariff.
Does standby mode matter?
Yes, though usually small (<1 W). Over a year it can add €5-10 per device.
How do I convert W to kWh?
Divide the power (W) by 1000 and multiply by hours of use. 2000 W × 1 h = 2 kWh.
Does the formula work for any appliance?
Yes, as long as you have the power in W. For appliances with a compressor (fridge, AC) use the average power, not the peak.