SEER Energy Cost Calculator
A SEER energy cost calculator estimates how much it costs to run an air conditioner or heat pump in cooling mode over a season. SEER stands for seasonal energy efficiency ratio, the cooling output in BTU divided by the electrical energy in watt hours over a typical cooling season. A higher SEER number means more cooling for each unit of electricity, so it costs less to run. This tool divides the cooling capacity in BTU per hour by the SEER rating to get average power draw in watts, multiplies by the run hours to get kilowatt hours, then multiplies by your electricity rate to get the running cost. The cooling capacity, SEER rating, run hours and electricity rate are all editable so you can model your own equipment and utility tariff. The US Department of Energy sets minimum SEER standards and publishes guidance on cooling efficiency and operating cost. Use the result to compare two units side by side, justify an upgrade to a higher rating, or simply budget for a summer of running cost. Every figure is computed deterministically from the formula shown below, with a worked example that reconciles exactly to the calculator so you can follow each step yourself.
Running cost divides cooling BTU by SEER for watts, then bills the kilowatt hours: cost = (BTU / SEER) / 1,000 x hours x rate. A 24,000 BTU unit at SEER 16 running 1,000 hours at $0.15/kWh costs $225.00.
SEER energy cost formula
Power (W) = BTU per hour / SEER
Energy (kWh) = Power / 1,000 x hours
Cost = Energy x rate
SEER is BTU of cooling per watt hour of electricity over a season, so dividing the BTU per hour rating by SEER gives the average watts the unit draws while cooling.
Worked example
A 24,000 BTU per hour air conditioner rated SEER 16 runs 1,000 hours over the season at an electricity rate of $0.15 per kilowatt hour.
- Power = 24,000 / 16 = 1,500 W
- Energy = 1,500 / 1,000 x 1,000 = 1,500 kWh
- Cost = 1,500 x 0.15 = $225.00
Running this unit for the season costs $225.00. These are the calculator's default inputs, so the result above matches the widget exactly.
SEER Energy Cost Calculator: frequently asked questions
What does SEER mean?
SEER stands for seasonal energy efficiency ratio. It is the total cooling output in BTU over a typical cooling season divided by the total electrical energy used in watt hours. A higher SEER means the unit produces more cooling for each unit of electricity, so it costs less to operate. Newer units carry SEER2, a similar measure tested under updated conditions.
How do I find my run hours?
Cooling run hours depend on your climate, thermostat setting and how well the home is insulated. A rough seasonal figure for a hot region might be 1,000 to 2,000 hours, while a mild climate may be a few hundred. Check past utility bills or a smart thermostat report for a figure specific to your home.
Is a higher SEER always cheaper to run?
For the same cooling load, a higher SEER unit always uses less electricity, so each hour of running costs less. Whether it pays back the higher purchase price depends on how many hours you run it and your electricity rate. Run the numbers for both units to compare lifetime cost, not just running cost.
Why divide BTU by SEER?
SEER is defined as cooling BTU per watt hour of electricity over a season, so the BTU per hour rating divided by SEER gives the average electrical power in watts while the unit is cooling. Multiplying that power by run hours gives energy use, and energy times rate gives cost.
Does this include heating?
No. SEER measures cooling efficiency only. Heat pumps have a separate heating efficiency measure called HSPF. This calculator estimates cooling season running cost. For heating cost, use a furnace or heat pump heating calculator instead.
Official sources
- Cooling efficiency, SEER standards and operating cost guidance: US Department of Energy (DOE). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.