Appliance running costs
Cost to run an air conditioner
How much does a 1,200 W air conditioner cost to run?
A 1,200 W air conditioner switched on 8 hours per day at 60% duty cycle uses 5.79 kWh of electricity per day. At $0.180/kWh that is $1.04 per day, about $31.73 per average month and $380.79 per year — 2,115 kWh over the year. Those figures assume a typical wattage and a typical usage pattern; change any input below to match your own appliance and tariff.
Your inputs
Typical example — replace this 1,200 W default with your appliance’s actual rating for a better estimate.
This appliance cycles — typical range around 60%.
Applies only to the 16 h a day the appliance is switched off, not to the idle part of the duty cycle.
Use the total variable rate from your bill, including delivery charges per kWh.
$31.73
per month (30.44-day average month)
5.79 kWh per day at 1,200 W
- Per day
- $1.04
- kWh / month
- 176
- kWh / year
- 2,115
- Per year
- $380.79
Average power across 24 hours
241 W
Daily energy spread evenly over 24 hours. Includes standby draw during switched-off hours when entered.
Cost per running hour
$0.130
While the appliance is actually drawing power.
Effective duty cycle
60%
Share of switched-on time at rated power.
Method
- 1,200 W = 1.2 kW
- 1.2 kW × 8 h/day × 60% duty = 5.76 kWh/day active
- 2 W standby × 16 h/day off = 0.032 kWh/day standby
- 5.76 + 0.032 = 5.792 kWh/day total
- 5.792 kWh × 0.18 USD/kWh = 1.043 USD/day
- 1.043 × 30.436875 days = 31.732 USD/month
- 5.792 kWh × 365.2425 days = 2115.485 kWh/year
- 2115.485 kWh × 0.18 USD/kWh = 380.787 USD/year
Monthly figures use a 30.44-day average month, 365.24-day average year.
Assumptions
- Electricity rate of 0.18 USD/kWh (editable).
- Calculations use a year of 365.2425 days and an average month of 365.2425 ÷ 12 = 30.436875 days, so twelve average months equal one year exactly. Displayed values are rounded to 365.24 and 30.44 days, and the rounded figures do not multiply out exactly.
- Duty cycle of 60% — the appliance draws rated power for that share of the time it is switched on.
- 2 W standby draw for the 16 hours a day the appliance is switched off. Standby applies only outside the switched-on hours, not to the idle part of the duty cycle, and is included in every kWh and cost figure below.
- Rated power is treated as real power in watts, not volt-amps.
What can change the result?
- Compressor duty cycle, which tracks outdoor temperature
- Whether the unit is single-speed or inverter-driven
- Thermostat setpoint and room insulation
- Unit efficiency (EER/SEER) — the same cooling can need very different input power
$31.73/mo · 176 kWh/mo
How a air conditioner actually draws power
An air conditioner is a heat pump running in reverse, and its input power is not fixed. A single-speed unit cycles the compressor on and off — the fan keeps running, the compressor does not. An inverter unit instead modulates, drawing high power to pull the room down and then settling at a much lower steady draw. Input power also rises as outdoor temperature rises, because the machine has to reject heat against a hotter outside.
The duty cycle below matters more than the wattage. On a mild day a unit may run 30% of the time; during a heatwave it can approach 100%. Cooling capacity in BTU is not electrical power — divide BTU/h by the unit's EER to get watts drawn.
Cost at different usage patterns
All rows use 1,200 W at 60% duty and $0.180/kWh. Only the hours change.
| Hours per day | kWh per day | Per day | Per month | Per year |
|---|---|---|---|---|
| 4 h/day | 2.92 kWh | $0.53 | $16.00 | $191.97 |
| 6 h/day | 4.36 kWh | $0.78 | $23.86 | $286.38 |
| 8 h/day | 5.79 kWh | $1.04 | $31.73 | $380.79 |
| 12 h/day | 8.66 kWh | $1.56 | $47.47 | $569.60 |
Cost across the typical wattage range
Units in this category typically range from 500 W to 3,500 W. All rows use 8 h/day at 60% duty.
| Power rating | kWh per day | Per day | Per month | Per year |
|---|---|---|---|---|
| 500 W | 2.43 kWh | $0.44 | $13.32 | $159.89 |
| 1,200 W | 5.79 kWh | $1.04 | $31.73 | $380.79 |
| 3,500 W | 16.8 kWh | $3.03 | $92.22 | $1,107 |
Worth knowing
Worth knowing
Your next decision
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- Why the rating plate overstates what this appliance usesDuty cycle and part-load operation, which set the figures above.
- What the standby watts add over a yearThe off-hours component of this appliance's annual total.
Your next decision
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Electricity cost tools
- Electricity cost calculatorWatts and hours in, cost per day, month and year out.
- Cost per kWh explainedThree different costs per kWh on one bill, and which one belongs in a calculator.
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Defaults on this page come from the published default registry and the formulas are documented in the methodology.