Air Conditioner Running Cost Calculator
Estimate cooling costs from the two numbers on your unit's label: BTU capacity and SEER2 (or EER) efficiency.
Cooling cost
| Power draw while running | — |
| Cost per hour of cooling | — |
| Cost per day | — |
| Cost per month | — |
| Cost per season | — |
Estimates assume steady compressor draw at rated efficiency; real usage varies with weather, thermostat setting, insulation, and duct losses. Rates: EIA, April 2026.
How this is calculated
Power draw (W) = BTU/hr ÷ EER, where EER ≈ SEER2 × 0.875 if you enter SEER2. Then cost = kW × compressor hours × rate. Monthly uses 30.44 days; the season multiplies by your cooling months. This is the standard engineering estimate — it won't capture your exact duty cycle, but it's within the right range for budgeting.
FAQ
How much electricity does an air conditioner use?
Divide cooling capacity by efficiency: a 12,000 BTU/hr unit at SEER2 14 (≈ EER 12.25) draws about 980 W while the compressor runs. At 8 compressor-hours a day and the US average rate, that's about $1.48 per day.
What's the difference between SEER2 and EER?
EER is efficiency at one fixed test condition; SEER2 averages over a simulated cooling season, so it reads higher. For power-draw estimates, EER ≈ SEER2 × 0.875 is the common approximation, and it's what this calculator uses.
Why "compressor hours" instead of hours the AC is on?
A correctly sized AC cycles — the compressor typically runs 50–80% of the time the unit is "on" in hot weather. If your AC is on 12 hours a day, 7–9 compressor-hours is realistic.
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