Calculate your heating or cooling electricity cost
Start with the example below, then replace every input with your own figures. The result estimates electricity for the equipment you include, not a complete utility bill or an installation quote.
What could your system cost to run?
Example inputs are filled in. Replace them with your own figures for a useful estimate.
Your equipment and usage
Your estimate
- Total electricity
- 360 kWh
- Electricity per day
- 12 kWh
- Cost per day
- USD 1.80
2 kW × 6 hours × 30 days × 0.15 USD/kWh
An electricity-only estimate at the entered power and rate. Excludes standing charges, fuel, installation, and maintenance. Variable-speed operation and auxiliary heat can change actual use.
Where to find the numbers
Use electrical input power in kilowatts. Cooling capacity in BTU/h, heating output, and system tonnage are different quantities: entering them as electrical power will produce an incorrect result. Look for manufacturer operating data or ask your contractor for an appropriate input-power estimate. A maximum electrical rating is not necessarily normal consumption.
Operating hours means time actually running at the entered power, not the time the thermostat is switched on. If your equipment cycles or changes speed, use an equivalent runtime or a representative average power for that runtime. A thermostat runtime report can help, but a variable-speed system may consume different amounts during each hour.
- Convert watts to kilowatts by dividing by 1,000.
- Use your electricity unit rate, including variable delivery charges where appropriate.
- Enter 0.15 for 15 cents per kWh, or 0.25 for 25 pence per kWh.
- For time-of-use pricing, calculate each rate period separately and add the costs.
The formula, with a worked example
Electricity use in kWh = input kW × operating hours per day × number of days. Estimated cost = kWh × price per kWh. This is the energy calculation described by Virginia Tech's energy-use guide.
For an illustrative 2 kW load running six hours a day for 30 days, electricity use is 360 kWh. At 0.15 per kWh, the cost is 54 in your selected currency. These are example inputs, not typical HVAC consumption or a local tariff.
| Example input | Value |
|---|---|
| Electrical input | 2 kW |
| Runtime | 6 hours/day for 30 days |
| Electricity use | 360 kWh |
| Unit rate | 0.15 per kWh |
| Estimated cost | 54.00 |
What the estimate includes and leaves out
The calculation assumes a constant input power and electricity rate for the hours entered. Weather, insulation, thermostat choices, equipment condition, defrost cycles, and variable-speed operation can change actual consumption. Auxiliary resistance heating and separate indoor fans need to be included in your power figure or calculated separately.
Standing charges, financing, servicing, installation, and gas or oil use are excluded. Selecting another currency changes the label only; it does not convert prices or look up local rates. For a purchase decision, request an estimate based on your home and climate and compare it with your own usage history.
Use the result to ask better questions
Take the inputs and result to your contractor. Ask which components the estimate covers, how the power figure was chosen, and how heating-season performance differs from cooling. Use our quote comparison guide to check the rest of the proposal, compare maintenance plans and individual visits, or read repair versus replacement.