Air Conditioner Electricity Cost Calculator

Estimate what an air conditioner costs to run for a usage scenario you describe — not a prediction of your exact bill. Enter watts if you know them. If you only know BTU and SEER, the result is a clearly labelled approximation, not a measurement.

Calculate running cost

Watts is electrical input power. BTU/h is cooling capacity — a different quantity, and never a substitute for watts.

Electrical input power (watts) — preferred, if known W

Electrical input from the label or manual, not BTU/h.

Hours per day hours/day

How long it runs at that power each day.

Days per month days/month

Days in the month you are estimating.

Your electricity rate per kWh — check your bill; no tariff is assumedper kWh

Your own rate from your bill. No tariff is assumed.

Currency

Optional: BTU and SEER (approximation only)

Leave these blank if you entered watts. If watts are blank and both BTU/h and SEER are entered, estimated watts are calculated as BTU/h divided by SEER. That is a seasonal-average approximation: SEER is a seasonal rating, not the power draw at any one moment.

Cooling capacity (BTU/h) — optionalBTU/h

Cooling capacity, optional. Never use this as watts.

SEER rating — optionalSEER

Seasonal rating, optional. Needed together with BTU/h for an approximation.

No calculation yet — enter values above and choose Calculate running cost.

Per day—Enter values above

Per month—Enter values above

Estimated monthly cost—Enter values above

Mode: no calculation yet. Enter watts for a watts-based estimate, or BTU and SEER together for a labelled approximation.

Estimation disclaimer: this is an estimate for a scenario you entered. It assumes the air conditioner draws the entered watts for the entered hours. Real use differs with cycling, variable-speed operation, weather, insulation, thermostat settings, and load. Taxes, fixed charges, and time-of-use tariffs are excluded unless your rate already includes them.

How it works

kWh = watts × hours ÷ 1,000
Cost = kWh × your rate

BTU/SEER approximation, when watts are not entered: estimated watts = BTU/h ÷ SEER. Example: 12,000 BTU/h ÷ SEER 16 = 750W estimated input, before the kWh formula above. That estimate is labelled as an approximation wherever it appears.

Cooling capacity vs electrical input

BTU/h measures how much heat the unit can move. Watts measure how much electricity it draws to do that. A larger BTU number does not mean a larger electricity bill by itself — efficiency matters. That is why BTU/h must never be used as if it were watts: 12,000 BTU/h is not 12,000W. Likewise, SEER is not an exact real-world efficiency prediction for your home, your climate, or a single hot afternoon.

If your unit's label or manual gives input watts, use watts. If it gives only BTU and SEER, use the approximation mode and treat the result as a range to sanity-check, not a bill forecast.

Examples

Example (watts mode): 1,000W × 8 hours/day × 30 days = 240 kWh/month. At a rate you enter, the monthly cost is 240 × that rate. No rate is assumed in the example — enter your own.

Why actual use differs from rated estimates

Cycling: a unit switches on and off with the thermostat; it rarely draws full power continuously.
Variable speed: inverter units vary their draw instead of running at one fixed power.
Weather and insulation: hotter days, poorer insulation, and open doors raise the load.
Settings: a lower set temperature and higher fan speed change both run time and power.
Your tariff: time-of-use, tiered, and fixed charges are not modelled here unless your entered rate already includes them.