Calculate your cost
Start with a representative input, then edit all three numbers.
This setup uses about 840 kWh in a 30-day month.
Please enter valid values within the ranges shown.
| Schedule | Hours/day | Cost/month |
|---|---|---|
| Half runtime | 4 | $79.09 |
| Starting point | 8 | $158.17 |
| Longer runtime | 12 | $237.26 |
Same 3,500-watt input and 18.83¢/kWh rate; only runtime changes.
The quick formula
3.5 kW × 8 hours × $0.1883 = $5.27 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
Central air conditioning is often one of a home's largest summer electricity loads. The actual draw changes as the compressor cycles, so use the nameplate or monitoring data when you want a closer estimate.
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
Cooling capacity and system efficiency rating
- 02
Outdoor temperature, humidity, and thermostat setting
- 03
Home size, insulation, duct leakage, and compressor runtime
Ways to spend less
- Raise the thermostat a few degrees when the home is empty.
- Replace dirty filters and keep outdoor coils clear.
- Seal duct leaks and shade sun-facing windows before oversizing equipment.