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Appliance electricity cost calculator
Convert appliance watts and usage hours into monthly kWh and electricity cost using your own tariff.
Appliance electricity cost
See what one device costs to run each month.
Estimated monthly cost
Formula: watts ÷ 1,000 × hours × days × price
Explainable maths
Every result uses a short, visible formula.
No hidden assumptions
Prices and usage are always yours to enter.
How to use this calculator
Read the input power in watts from the appliance label or documentation, then enter average operating hours per day and days per month. Use the electricity price from your own contract. This estimates one appliance, not the full household bill. The starting price is only an example.
Worked example
A 1,200 W appliance running two hours per day for 30 days uses 1,200 ÷ 1,000 × 2 × 30 = 72 kWh. At €0.25/kWh it costs €18. Halving its operating time halves the estimated energy and cost, provided its power stays the same.
Can I use the label wattage for a fridge?
Label power is not necessarily average power. Fridges cycle on and off, and heaters and air conditioners may vary their output. Use measured average consumption or the energy label’s annual kWh for a more representative estimate.
Which electricity price should I enter?
Use the per-kWh charges that apply to that consumption, including applicable variable charges and taxes. Fixed daily or monthly fees are not included. If rates change by time of day, calculate each period separately and add the results.