Practical AtlasIndependent reference
ESP
KOR
JPNEV-G15Everyday reference
How much electricity does an air conditioner use?
BTU/h describes heat removed; watts describe electricity drawn. Use the equipment label or measured input for a cost estimate, then account for runtime and cycling.
Screen a cooling capacity range ↗BTU/h and watts answer different questions
Cooling capacity is the rate of heat removal. Electrical input is the power drawn from the circuit. Two units with the same BTU/h can have different input power and efficiency.
Start with the nameplate or EnergyGuide
Use the rated watts, amps and volts, or an annual kWh figure when supplied. If you only have amps and volts, watts are approximately volts multiplied by amps; real equipment can vary while starting or cycling.
| What you have | What it tells you |
|---|---|
| BTU/h | Cooling capacity |
| Watts | Electrical input at the rated condition |
| Annual kWh | A standardized usage estimate |
| Your bill rate | Local cost per kWh |
Runtime is the biggest swing factor
A unit that runs 30% of the hour uses far less than one that runs continuously. Track a hot day and a mild day separately, and do not turn a short heat wave into a full-season promise.
Planning boundary: the cooling estimator is a screening tool. Insulation, leakage, sunlight, connected rooms, maintenance, and climate can change the load and the actual bill.
2 SOURCESSource ledger
Check the basis.
QUESTIONS THIS ANSWERS
Questions this answers
- How many kWh does an AC use per hour?
- Why is an AC BTU rating not the same as watts?