How much does it cost to run a central air conditioner?
We've pre-filled a typical central air conditioner below. Set your electricity rate and adjust the hours to match how you use yours — the cost updates instantly.
Typical power 3,500W
Usual range 2,000–5,000W
Category Heating & cooling
Central air is usually the heavyweight on a summer electric bill. The outdoor compressor draws several thousand watts whenever it's actively cooling — but it doesn't run continuously. On a hot day it might cycle on for 6–9 hours' worth of run time spread across 24 hours, which is what this estimate is modelling.
Because the run time scales with how hard your house has to fight the outdoor heat, small changes to the thermostat and the building envelope move this number more than anything you can do to the unit itself.
What drives the cost of running a central air conditioner
- Cooling run time climbs fast as the gap between your thermostat and the outdoor temperature grows.
- An older or low-SEER unit does the same cooling for noticeably more watts.
- Leaky ducts, poor insulation and a clogged filter all make it run longer for the same comfort.
How to cut it
- Each degree warmer on the thermostat cuts run time by roughly 3–5% — 78°F costs far less than 72°F.
- A programmable or smart thermostat that eases off while you're out is the highest-value change.
- Replace the air filter on schedule and keep the outdoor coil clear so the compressor isn't fighting itself.
- Ceiling fans let you feel comfortable a couple of degrees warmer for ~65W instead of thousands.