Air conditioner cost calculator
How Much Does an Air Conditioner Cost to Run?
Estimate how much an air conditioner costs to run per hour, day, month, and year using your electricity price and the unit's wattage.
Cost estimate
Calculate your electricity cost
Estimated energy use0 kWh/day
Estimated monthly energy0 kWh/month
Cost = watts ÷ 1,000 × hours used × electricity price.
Example
A quick way to sanity-check the result
With the example settings of 1,000 watts for 8 hours a day, the unit uses 8 kWh per day before accounting for any thermostat cycling. Enter the actual power draw of your equipment for a better estimate.
Actual electricity use can vary with power settings, thermostat cycling, efficiency, standby use, and how the appliance is operated.
Rated power vs actual use
An air conditioner rarely draws its nameplate power every minute it is switched on.
The compressor is the largest electrical load in a conventional air conditioner. Once the room reaches the thermostat setting, the compressor can cycle off while the fan continues or the entire system pauses. Using rated input power for every hour therefore gives a simple upper-style estimate rather than a guaranteed bill.
Outdoor temperature, indoor humidity, insulation, sun exposure, equipment size, thermostat setting, and how often doors open all affect compressor runtime.
BTU and watts measure different things
Cooling capacity is not the same as electrical input.
BTU per hour describes how quickly an air conditioner can move heat. Watts describe the electrical power it consumes. Two units with the same cooling capacity can use different amounts of electricity because their efficiency differs.
If a manufacturer provides an input-watt figure, use that here. If you only know cooling capacity, do not enter the BTU number as watts.
A better real-world estimate
Use measured average power when you can.
For window and portable units, a plug-in energy monitor can capture cycling over several hours. For central equipment, utility interval data or an HVAC energy monitor can help. A hot afternoon and a mild evening can produce very different hourly averages even with the same thermostat.
For the general power-and-time method, see How to Estimate an Appliance's Electricity Cost.