Cost to run

How much does central air conditioning cost to run?

Central AC is usually the largest single electricity load in a cooling-season bill. Cost depends on system wattage, how many hours the compressor actually runs, and your electricity rate.

Reviewed 2026-07-15 · methodology appliance-energy-1.0.0 · data vintage 2026-04-ytd

Example costs using the Texas state-average rate

These are generated examples for a consistent location. Enter your own ZIP and usage below for a more relevant state-average estimate.

Scenario	Assumption	kWh/month	Monthly range	Most likely/year
Mild weather	4 hours a day with light compressor cycling	210.00	$22.37–$49.92	$410.84
Typical summer	8 hours a day with moderate cycling	504.00	$53.68–$119.81	$986.03
Heat wave	12 hours a day with the compressor mostly on	1071.00	$114.08–$254.61	$2,095.30

Source: U.S. Energy Information Administration, Electric Power Monthly Table 5.6.B. Data vintage 2026-04-ytd. State-average pricing is not your exact utility tariff.

Calculate your own usage

Your inputs

ZIP code

Used to pick your state’s average electricity rate. We don’t need your street address.

ApplianceHow manyHours used per day (optional)

Leave blank to use a typical default for this appliance.

Rated watts (from the appliance label)Duty cycle (0–1; share of time drawing full power)Days per month

Your estimate — a range, confidence level, and the sources behind it — will appear here.

What drives central AC running cost?

Outdoor temperature, thermostat setting, home size, insulation, duct condition, and system efficiency decide how long the compressor runs each day. The compressor and outdoor fan are the dominant loads, and their combined wattage varies with system tonnage and SEER rating.

Finding your system's real wattage

Check the outdoor unit's nameplate for rated load amps and voltage, or look up the model's cooling capacity and SEER rating. A rough conversion is capacity in BTU per hour divided by SEER, which yields average watts during operation.

What this cooling estimate leaves out

The model does not simulate weather, thermal load, or thermostat schedules, and it cannot compare specific SEER ratings or refrigerant conditions. Duct leakage, shading, and humidity also shift real consumption, so treat the range as a planning band rather than a bill prediction.

Frequently asked questions

Why is my summer electric bill so much higher?

Cooling runtime rises quickly with outdoor heat. A system that runs four hours a day in mild weather can run twelve or more during a heat wave, tripling its share of the bill.

Does a bigger house always mean higher AC cost?

Not automatically. Insulation, air sealing, window orientation, and system efficiency can matter as much as floor area. Two same-size homes can have very different compressor runtimes.

Should I use rated watts or measured watts?

Measured average watts from an energy monitor is best. If you only have the nameplate, enter it and use the duty-cycle input to represent compressor cycling.

Related appliance cost guides

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