How to calculate electricity cost
Electricity is billed in kilowatt-hours (kWh). To find an appliance's usage, multiply its wattage by the hours it runs, then divide by 1,000 — a 1,500 W space heater running 2 hours uses 3 kWh. Multiply kWh by your electricity rate to get the cost. This calculator does that for a single appliance and shows the daily, monthly and yearly cost.
Your actual bill will be higher than the estimate because utilities add fixed charges, taxes and distribution fees. And devices rarely draw exactly their rated wattage — a "1,500 W" heater might cycle between 1,000 W and 1,500 W. Treat the result as a realistic baseline and compare it across appliances.
Common appliances and their typical draw
- Space heater: ~1,500 W
- Window air conditioner: ~1,000-1,400 W
- Refrigerator: ~100-200 W (continuous)
- LED bulb: ~8-12 W