The short answer
Heating an average 1,800 sq ft house with a gas furnace costs about $155.81 in January and $802.00 a year at U.S. average prices and climate. A heat pump costs about $226.50 in its peak month, propane $293.55 and electric baseboard $532.32. Where you live matters most: the same house with gas costs about $182.49 in a Minnesota January, while a heat pump in Texas costs about $82.38 in its coldest month.
The same house in every state
Natural gas furnace, 1,800 sq ft house with average insulation, at each state's prices and winters.
| Alabama | $114.48 | $464.42 | $470.05 | 16.33¢ |
|---|---|---|---|---|
| Alaska | $194.48 | $1,081.44 | $1,300.03 | 29.41¢ |
| Arizona | $88.98 | $352.37 | $357.96 | 15.05¢ |
| Arkansas | $153.32 | $645.07 | $657.67 | 14.37¢ |
| California | $115.77 | $571.54 | $621.69 | 29.75¢ |
| Colorado | $132.36 | $709.61 | $793.68 | 17.17¢ |
| Connecticut | $193.13 | $930.37 | $987.27 | 24.51¢ |
| Delaware | $152.62 | $697.62 | $719.45 | 18.70¢ |
| District of Columbia | $162.58 | $741.92 | $765.91 | 25.98¢ |
| Florida | $53.32 | $165.35 | $165.35 | 14.99¢ |
| Georgia | $135.91 | $567.23 | $576.26 | 15.90¢ |
| Hawaii | $0.00 | $0.00 | $0.00 | 47.18¢ |
| Idaho | $89.99 | $470.02 | $529.79 | 13.37¢ |
| Illinois | $144.15 | $657.34 | $693.46 | 19.32¢ |
| Indiana | $135.57 | $618.39 | $650.78 | 17.02¢ |
| Iowa | $149.56 | $683.16 | $725.04 | 17.06¢ |
| Kansas | $157.52 | $699.65 | $726.78 | 15.47¢ |
| Kentucky | $136.49 | $605.77 | $627.61 | 13.80¢ |
| Louisiana | $80.36 | $289.05 | $289.22 | 12.87¢ |
| Maine | $270.23 | $1,334.94 | $1,479.87 | 32.11¢ |
| Maryland | $157.53 | $718.88 | $742.12 | 21.40¢ |
| Massachusetts | $296.07 | $1,444.04 | $1,546.93 | 30.48¢ |
| Michigan | $141.37 | $685.30 | $738.15 | 22.99¢ |
| Minnesota | $182.49 | $867.14 | $942.69 | 17.20¢ |
| Mississippi | $101.00 | $398.14 | $400.66 | 14.43¢ |
| Missouri | $163.57 | $717.75 | $747.46 | 16.02¢ |
| Montana | $118.41 | $655.95 | $774.99 | 15.57¢ |
| Nebraska | $145.24 | $678.50 | $720.00 | 13.54¢ |
| Nevada | $96.22 | $433.04 | $456.86 | 12.72¢ |
| New Hampshire | $257.73 | $1,276.29 | $1,397.28 | 27.64¢ |
| New Jersey | $150.05 | $705.99 | $737.97 | 24.61¢ |
| New Mexico | $88.01 | $420.26 | $441.74 | 16.51¢ |
| New York | $207.10 | $997.93 | $1,062.95 | 28.65¢ |
| North Carolina | $123.98 | $540.72 | $553.07 | 14.95¢ |
| North Dakota | $163.94 | $801.41 | $880.60 | 13.31¢ |
| Ohio | $160.87 | $751.41 | $794.28 | 19.38¢ |
| Oklahoma | $120.37 | $502.64 | $512.05 | 14.82¢ |
| Oregon | $138.92 | $757.02 | $883.86 | 15.92¢ |
| Pennsylvania | $170.90 | $813.40 | $861.30 | 21.77¢ |
| Rhode Island | $242.41 | $1,176.12 | $1,254.75 | 28.18¢ |
| South Carolina | $106.50 | $435.36 | $439.44 | 15.76¢ |
| South Dakota | $142.16 | $694.88 | $755.87 | 15.15¢ |
| Tennessee | $99.67 | $434.33 | $445.86 | 13.42¢ |
| Texas | $95.68 | $353.31 | $354.67 | 15.91¢ |
| Utah | $120.82 | $633.80 | $712.64 | 13.31¢ |
| Vermont | $265.10 | $1,319.51 | $1,461.49 | 23.84¢ |
| Virginia | $152.45 | $694.53 | $719.01 | 17.64¢ |
| Washington | $154.66 | $846.11 | $993.86 | 14.63¢ |
| West Virginia | $142.62 | $665.56 | $702.29 | 16.31¢ |
| Wisconsin | $157.58 | $752.69 | $815.99 | 19.41¢ |
| Wyoming | $153.79 | $839.85 | $968.56 | 14.43¢ |
Winter is October to April. Gas prices are each state's 2025 average; propane and heating oil the state's, region's or U.S. average over winter 2025-26. Degree days are population-weighted state averages by month for 1991-2020 (Alaska: Anchorage; Hawaii: Honolulu). With a ZIP code, your own result uses the normals of the weather station nearest the county's center of population; the state table keeps the state averages.
How it works
The formula
cost a year = heat ÷ efficiency ÷ BTU per unit × price
cost in a month = cost a year × that month's degree days ÷ the year's
Assumptions
- Heat-loss factor: 8, 5.5 or 3.5 BTU per square foot per degree day for poor, average or good insulation, set so an average 1,800 sq ft Ohio house needs about 600 therms of gas a year. Your house can differ; your own past bills are the best check.
- Degree days by month are NOAA's population-weighted state averages for 1991-2020, or with a ZIP code the 1991-2020 normals of the nearest weather station. A real month can be colder or warmer than average.
- Heat pumps: we use one seasonal efficiency for the whole year (HSPF2 ÷ 3.412, adjusted for the state's climate). In reality a heat pump is less efficient in the coldest months and more in mild ones, so its January cost runs higher and its fall and spring costs lower than shown.
- Prices are state averages, which include fixed monthly charges spread over usage. Your bill also has a fixed customer charge every month, even in summer. Type the per-unit price from your bill for the closest result.
- Heat content (EIA): 100,000 BTU per therm, 91,452 per gallon of propane, 137,381 per gallon of heating oil, 3,412 per kWh.
Worked example: gas heat at U.S. averages
1,800 sq ft, average insulation, 95% gas furnace, gas $1.48 per therm
- Heat a year: 1,800 × 5.5 × 5,200 = 51.5 million BTU
- Gas: ÷ 0.95 ÷ 100,000 = 542 therms × $1.48 = $802.00 a year
- January has 1,010 of the year's degree days, so it costs $155.81
Ways to cut the cost
- Turn it down. With a furnace, 7 to 10°F lower for 8 hours a day saves up to 10% a year. With a heat pump, keep setbacks small (2 to 3°F).
- Seal and insulate. Drafty doors, windows and attic hatches are the cheapest fixes; attic insulation is next.
- Budget billing. Most utilities and propane dealers can spread the winter cost over 12 equal payments.
- Buy propane or oil early. Fill the tank before winter, or ask about a pre-buy or capped-price plan.
- Service the system. A clean filter and a yearly tune-up keep a furnace or heat pump near its rated efficiency.
Questions people ask
How much does it cost to heat a house per month?
For an average 1,800 sq ft house with a gas furnace at U.S. average prices, about $155.81 in January, the coldest month, and $802.00 for the year. Most of that falls between November and March. Cold states pay much more: in Minnesota the same house costs about $182.49 in January. Pick your state and heating system above.
Which heating is cheapest to run?
At U.S. average prices, for the example house: natural gas about $802.00 a year, a heat pump $1,165.83, propane $1,510.99, oil $1,767.82 and electric baseboard $2,739.97. The ranking changes by state; the heat pump vs furnace calculator compares them side by side for yours.
Why is my heating bill highest in January?
Heating cost follows heating degree days, a measure of how far below 65°F the outdoor temperature is and for how long. January is the coldest month in almost every state, so it has the most degree days and the biggest bill. A month twice as cold costs about twice as much to heat.
How much propane does a house use a month in winter?
About 115 gallons in January for the example house with a 95% propane furnace, and 593 gallons over a year, in a typical U.S. climate. A cold-state house can use twice that. Order before the first cold snap: prices usually rise during the winter.
How can I lower my winter heating bill?
Turn the thermostat down at night and when you're out, seal drafts around doors and windows, and add attic insulation: going from poor to average insulation cuts the heat a house needs by about a third. The dollar savings are biggest where winters are cold and fuel is expensive: try both insulation settings above for your state.