Calculate your cost
Start with a representative input, then edit all three numbers.
This setup uses about 9 kWh in a 30-day month.
Please enter valid values within the ranges shown.
| Schedule | Hours/day | Cost/month |
|---|---|---|
| Half runtime | 0.13 | $0.85 |
| Starting point | 0.25 | $1.69 |
| Longer runtime | 0.38 | $2.54 |
Same 1,200-watt input and 18.83¢/kWh rate; only runtime changes.
The quick formula
1.2 kW × 0.25 hours × $0.1883 = $0.06 per day
Convert watts to kilowatts, multiply by the active hours used each day, then multiply by the electricity price in dollars per kWh. Multiply the daily result by 30 for the monthly estimate shown above.
How to read this estimate
A microwave has a fairly high draw while running but is normally used for only a few minutes at a time. Its short runtime often makes the total cost small even when the input wattage looks similar to a compact heater.
The starting values keep this page useful before you have a label or meter reading. They do not describe every model, climate, operating mode, or household.
What changes the cost?
- 01
Input wattage rather than advertised cooking output
- 02
Minutes used per day and selected power level
- 03
Food quantity and repeated reheating cycles
Ways to spend less
- Enter actual minutes of daily use rather than rounding up to hours.
- Cover food appropriately to shorten reheating time.
- Use the microwave for small portions instead of preheating a full oven.