Calc4Living

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AC Running Cost Calculator

Estimate AC running costs from electrical input, or derive input power from cooling capacity and a clearly defined efficiency rating.

Your inputs

All fields are required. Prefilled values are an editable example, not local price or usage recommendations.

No exchange rates or conversion. Enter electricity prices in the selected currency per kWh, not in cents or pence. Changing currency clears the result.

Power drawn from the supply, not cooling or heating output. Select W or kW above.

0–24 equivalent hours at the entered or derived power. Account for cycling; this is not necessarily time switched on.

Enter major currency units per kWh: for example, 0.20 means 20 cents or pence, not 20.

Whole days, 0–366. The period result uses this value; monthly and annual comparisons use 30 and 365 days.

Your estimate

Energy & running cost

Review the example inputs, enter your local electricity price, then calculate. Results clear when inputs change so an old estimate is never shown for new values.

How much does it cost to run an air conditioner?

Direct input: cost = electrical kW × full-load-equivalent hours/day × days × rate. EER mode: electrical W = cooling BTU/h ÷ EER. COP mode: electrical kW = cooling kW ÷ cooling COP. 1 kW of cooling ≈ 3,412.141633 BTU/h.

Worked example

An AC rated at 12,000 BTU/h cooling with EER 12 draws an estimated 1,000 electrical W. At 6 full-load-equivalent hours/day and 0.20/kWh, it uses 6 kWh/day and costs 36.00 over 30 days.

Example amounts use whichever currency you select; they are arithmetic illustrations, not quoted local rates.

Assumptions & limitations

  • Cooling capacity is not electrical consumption. Prefer measured average input when available. EER here uses BTU/h per W; COP uses W/W. Do not substitute seasonal ratings such as SEER.
  • Enter full-load-equivalent hours: 8 hours switched on at an average 50% load is approximately 4 equivalent hours. This simple estimate does not model inverter curves, cycling or standby power.
  • Outdoor temperature, insulation, thermostat settings, fans and humidity affect consumption. Annual estimates repeat the entered daily usage for all 365 days; use a shorter selected period for a cooling season.

Further reading