What is the Electricity Cost Calculator?
The electricity cost calculator estimates how much an appliance adds to your power bill. Enter its wattage, the hours it runs and your tariff.
How to use the Electricity Cost tool
- Enter Appliance power, Hours used per day and Price per kWh.
- The result updates instantly as you type, or press Calculate.
- Use Try an example to see how it works, and Reset to start again.
Formula
Energy (kWh) = watts ÷ 1000 × hours. Cost = kWh × price per kWh.
Worked example
With appliance power 1500 watts, hours used per day 3, price per kwh 0.15, the cost per month comes to 20.25. Cost per day: 0.67; Cost per year: 246.37; Energy per day: 4.5 kWh.
Frequently asked questions
Where do I find the wattage?
Look at the label on the appliance or in its manual.
Is the estimate exact?
It assumes constant power. Devices that cycle on and off use less than their rated watts.
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Checked by Calcovate · Formula tested against worked examples · Updated 7 Nov 2026 · How we check our calculators.