AC Bill Calculator: Monthly Units & Cost

Estimate how many units your air conditioner uses and what it adds to your electricity bill. Enter the AC's average electrical input, your daily running hours and the price per unit from your own bill. The calculator works in your browser and does not send your inputs anywhere.

Quick answer: an air conditioner uses its average input in kilowatts × hours of use, measured in units (kWh). For example, an AC averaging 1,100 W for 8 hours a day uses 8.8 units a day, or 264 units in a 30-day month. Multiply the units by the price per unit on your bill to get the cost.

AC bill calculator

Average AC input (watts)

From the rating label or a measured average. See the questions below.

Hours per day

Days in the billing period

Number of ACs

Price per unit (kWh) from your bill

Any currency. Leave blank to see units only.

Enter the AC input and hours to see the result.

How the calculation works

Units (kWh) = average input in watts ÷ 1,000 × hours per day × days × number of ACs. Cost = units × your price per unit. One electricity unit on a bill is one kilowatt-hour.

For the full method behind appliance units, read how to calculate appliance electricity units.

Worked example

One AC with an average input of 1,100 W runs 8 hours a day for 30 days:

Daily units = 1,100 ÷ 1,000 × 8 = 8.8 kWh
Monthly units = 8.8 × 30 = 264 kWh
At an illustrative price of 50 per unit, the AC adds 264 × 50 = 13,200 to the bill

The price of 50 per unit is an invented teaching value, not a current tariff. Use the price printed on your own bill.

Monthly units by input and hours

Each cell is average input × hours a day × 30 days, for one AC. The inputs are example values; use the row closest to your own.

Average input	4 h/day	8 h/day	12 h/day
800 W	96	192	288
1,100 W	132	264	396
1,500 W	180	360	540
2,000 W	240	480	720

Slab tariffs: where the price per unit rises with monthly use, as in Pakistan and parts of India, the AC's extra units can move the whole bill into a higher slab. The cost then does not scale simply with units. Use your bill's slab table, or treat this result as units only.

Common questions

Which watts should I enter?

Enter the average electrical input while the AC runs, not the cooling capacity. The rating label lists electrical input in watts; cooling capacity in BTU/h or tons is a different measure. An inverter AC usually draws less than its maximum input once the room is cool, so a measured average gives a better estimate than the label maximum.

How can I measure the average input?

Read your electricity meter at the start and end of a session with other large appliances off, then divide the units by the hours. A split AC is usually hard-wired, so a plug-in meter often cannot be used. Electrical work should be left to a qualified electrician.

Why is my bill higher than this estimate?

The bill includes other appliances, fixed charges, taxes, adjustments and possibly a higher slab. Hot weather also makes the AC run longer than planned.

Does a higher thermostat setting reduce units?

Usually, because the compressor runs less to hold a warmer room. Measure your own use at different settings to see the effect in your home.

Related guides

Educational estimate only. It does not include start-up surges, fixed charges, taxes or tariff adjustments. Updated 8 November 2026 · Climate Calculator.