Air Conditioner Running Cost Calculator
Work out exactly what your air conditioner costs to run per hour, per night, per month and per year. Pick your AC size or type its wattage, set how long it runs and enter your electricity tariff — the calculator converts watts to units (kWh) and prices them instantly.
Air Conditioner Running Cost Calculator
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Tariff scope. The $0.17/kWh starting value is an illustrative input, not a verified live United States average or a supplier quote. Enter the variable rate from your bill. Fixed charges are excluded from individual appliance costs.
Power, usage, fuel prices and purchase prices are example assumptions. Grid-carbon factors are illustrative, not live or lifecycle data. Read our calculation and sourcing method.
How this calculator works
Compressors cycle on and off once the room reaches the set temperature, so a well-insulated room may draw only 50–70% of the nameplate wattage over a long session. Use the duty-cycle field to model that instead of guessing.
Worked example
A 1.5 ton inverter split rated at 1,400 W, running 8 hours a night: 1,400 ÷ 1000 × 8 = 11.2 kWh a night. At $0.17/kWh that is $1.90 a night, about $57 a month and roughly $228 across a four-month summer. Drop the duty cycle to 70% (realistic for an inverter in a shaded room) and the same AC costs about $40 a month.
Typical air conditioner power draw
| Unit type | Typical running watts | kWh per 8-hour night |
|---|---|---|
| 0.75 ton / 9,000 BTU inverter split | 600 – 800 W | 4.8 – 6.4 |
| 1.0 ton / 12,000 BTU inverter split | 800 – 1,000 W | 6.4 – 8.0 |
| 1.5 ton / 18,000 BTU inverter split | 1,200 – 1,600 W | 9.6 – 12.8 |
| 1.5 ton non-inverter split | 1,700 – 2,000 W | 13.6 – 16.0 |
| 2.0 ton / 24,000 BTU split | 2,000 – 2,400 W | 16.0 – 19.2 |
| Window AC 1.5 ton | 1,500 – 1,800 W | 12.0 – 14.4 |
| Portable AC | 1,000 – 1,400 W | 8.0 – 11.2 |
| Central AC, 3 ton | 3,000 – 4,000 W | 24.0 – 32.0 |
Six ways to cut your AC running cost
- Raise the setpoint by 1 °C. Every degree warmer typically trims 3–6% off compressor energy, and 24 °C is still comfortable for sleeping.
- Clean or replace filters monthly in season. A clogged filter forces longer compressor runtime for the same cooling and is the cheapest fix on this list.
- Run a ceiling fan with the AC. A 50 W fan lets you sit comfortably 2 °C warmer, which usually saves far more than the fan costs.
- Seal the room. Door gaps, open curtains on a sunny wall and unsealed window frames can add 20% or more to runtime.
- Use the sleep or eco timer. Cooling load drops after midnight, so a schedule that raises the setpoint at 1 am usually goes unnoticed.
- Service the outdoor coil once a year. A dusty condenser raises head pressure and pushes the compressor into a higher-power operating point.
Frequently asked questions
How much does it cost to run an air conditioner for 8 hours?
For a typical 1.5 ton inverter split drawing about 1,400 W, eight hours uses roughly 11.2 kWh. That is about $1.90 in the US, £2.77 in the UK, ₹90 in India or A$3.70 in Australia at average 2026 tariffs. Enter your own wattage and tariff above for an exact figure.
How many units does a 1.5 ton AC use per hour?
A 1.5 ton non-inverter split typically uses 1.7–2.0 units (kWh) per hour at full load. A modern inverter model of the same capacity uses about 1.2–1.6 units per hour at full load and considerably less once the room is at temperature, because the compressor throttles down instead of switching off and on.
Does an inverter AC really save money?
Yes, when it runs for long sessions. An inverter compressor modulates its speed and settles at a lower steady draw, which typically cuts consumption 20–40% versus a fixed-speed unit over a full night. For short 30-minute bursts the saving is much smaller because the unit spends most of that time pulling down the room temperature at full power.
Is it cheaper to leave the AC on all day or switch it on when needed?
For almost every household it is cheaper to switch it off. A cool empty room slowly leaks heat to the outside all day, and you pay for every joule of that leak. The exception is a very well insulated space with an inverter unit and a short absence, where the pull-down cost can exceed the idle cost.
What is the duty cycle field for?
Nameplate wattage is the draw at full load. Over a real night the compressor cycles, so the average is lower. Setting the duty cycle to 70% multiplies the result by 0.7 and gives a far more realistic monthly estimate than the nameplate figure alone.
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Choose a regional version for local context. The starting rates are examples; enter your own tariff.
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