Heating cost calculator

See what the same amount of heat costs from different fuels. Start with what you use now, and the calculator works out the heat your home receives and what that heat would cost with other systems. Prices come from the U.S. Energy Information Administration (EIA) and every number can be edited.

1. Your prices

State (sets electricity price)

Electricity ($ per kWh)

Natural gas ($ per therm)

Propane ($ per gallon)

Heating oil ($ per gallon)

Natural gas default is $1.43 per therm (national winter average of $14.85 per thousand cubic feet, converted at 10.36 therms per Mcf). Replace any price with the one on your bill.

2. How much heat do you use?

Your current heating

Annual use (therms)

Current efficiency (AFUE %)

Find annual use on your last twelve months of bills. Efficiency (AFUE) is on your furnace's label or manual; if unsure, 80 is a typical value for an older gas furnace. This is an assumption you can change.

3. Equipment to compare

Gas furnace AFUE %

Propane furnace AFUE %

Oil furnace AFUE %

Heat pump seasonal COP

How the math works

Heat your home receives = annual fuel use × energy content per unit × efficiency.
Energy content (EIA): natural gas 100,000 Btu per therm; propane 91,452 Btu per gallon; heating oil 138,500 Btu per gallon; electricity 3,412 Btu per kWh.
Cost to deliver one million Btu = price per unit ÷ (Btu per unit × efficiency ÷ 1,000,000). For heat pumps the efficiency is the COP.
Annual cost = cost per million Btu × million Btu of heat your home needs.

This ignores fixed charges, equipment cost, maintenance, distribution losses in ducts, and how heat pump performance changes in very cold weather. Treat results as a comparison of fuel cost, not a bid. For a replacement decision, see the repair vs replace calculator.

Frequently asked questions

Where do the prices come from?

Electricity: U.S. Energy Information Administration (EIA) Electric Power Monthly Table 5.6.A, average residential price by state for August 2026 (preliminary). Natural gas: a simple average of EIA national residential prices for November 2025 to March 2026. Propane and heating oil: EIA Heating Oil and Propane Update, U.S. average residential prices for the week of 11/09/2026.

Why is the natural gas price national and not by state?

EIA publishes state natural gas prices, but the latest month is a summer month, when residential gas prices are high because of fixed charges spread over little use. A winter-months national average reflects heating season better. You can replace it with the price on your own bill.

What does COP mean for a heat pump?

Coefficient of performance is heat delivered divided by electricity used. A COP of 2.5 means 2.5 units of heat for each unit of electricity. It varies with outdoor temperature and equipment. Our 2.5 default is an editable assumption, not an EIA or manufacturer value.

Sources

Electric Power Monthly, Table 5.6.A: Average Price of Electricity to Ultimate Customers by End-Use Sector, by State (August 2026, released October 23, 2026) (U.S. Energy Information Administration)
Natural Gas Monthly, Table 3: Selected national average natural gas prices (October 2026 release) (U.S. Energy Information Administration)
Heating Oil and Propane Update (weekly prices, week of 11/09/2026) (U.S. Energy Information Administration)
British thermal units (Btu): sample Btu conversion factors (U.S. Energy Information Administration)

Estimates only. Electricity prices are EIA's preliminary August 2026 residential averages; your utility's rates, tiers and time-of-use plans differ. Disclaimer.