Gas vs Electric Heating Cost in Illinois
In Illinois, a 2,000 sq ft house with average insulation costs an estimated $1,222.75 a year to heat with a 92% gas furnace, $5,897.92 with electric resistance heat and $2,359.17 with a heat pump. At these prices gas is the cheapest of the three, $1,136.42 a year under a heat pump.
State data
What Illinois pays
- Electricity
- 19.3¢/kWhEIA Electric Power Monthly, table 5.6.A · EIA, August 2026 (data as of 2026-10-25)
- Natural gas
- $1.08/thermEIA, residential natural gas price ($/Mcf ÷ 10.37) · EIA 2025 annual average (data as of 2026-10-25)
- Heating degree-days
- 6,200 °F-days (base 65 °F)NOAA CPC, 1991–2020 normals
- Climate zone
- 5 (IECC 2021)DOE/PNNL · heat pump seasonal COP used: 2.5
At 19.3¢/kWh, Illinois has the 18th-highest electricity rate among the 50 states and DC. Gas is $1.08/therm in Illinois, 27% below the US average of $1.48/therm and the 11th-lowest of the 51. At 6,200 heating degree-days, Illinois is in the 6,000-plus band on this site; the 2,000 sq ft example needs 104.2 MMBtu of heat.
Prices are statewide averages. Type the rate and gas price from your own bill into the calculator above to replace them.
How homes here heat
How homes in Illinois heat
- Main heating fuel
- Natural gas 78% · electricity 17% · propane 4% · fuel oil not reportedEIA RECS 2020, state tables · share of homes
- Main heating equipment
- Furnace 76% · central heat pump 2% · boiler 11%EIA RECS 2020, state tables · share of homes
- Homes using a secondary heater
- 39%EIA RECS 2020, state tables
- Household energy spend
- $1,720 a year, of which $606 on space heating (35%)EIA RECS 2020, state tables · average per household
- Share of home energy that is space heating
- 78% of natural gas use · 11% of electricity useEIA RECS 2020, state tables
Gas runs Illinois. In the 2020 survey, 78% of homes, about 3,800,000, named natural gas as their main heating fuel, the 2nd-highest share among the 50 states that report it and well above the national 51%. Electricity heats 17% of homes, against a US share of 34%, and propane 4%. Fuel oil is too uncommon for the survey to give a figure.
The equipment matches the fuel. 76% of homes heat with a furnace, the 10th-highest share, and 11% with a boiler. Central heat pumps are rare: 2% of homes, about 100,000, which is the lowest share of the 33 states the survey can measure, against 13% nationally. A secondary heater shows up in 39% of homes.
Heat is a big piece of a fairly ordinary energy bill. The average household spends $1,720 a year, the 36th-highest in the country, and $606 of it on space heating. That share, 35%, is the 11th-highest among the states, against 26% for the US, and heating accounts for 78% of the gas a household burns. Water heating, at $190, is a smaller slice here than nationally: 11% against 15%.
EIA RECS 2020, state tables: shares of all occupied homes in the state and average spending per household in the survey year. "Not reported" means EIA's sample was too small to publish a figure.
Gas vs electric heat
B04Scenario A
Sets the electricity rate. Pick US average if you're not sure.
From EIA for Illinois. Use the rate on your bill if you know it.
Rate used: 19.3¢/kWh · Illinois · EIA, August 2026 · gas $1.08/therm (EIA 2025 annual) · 6,200 heating degree-days · climate zone 5 (data as of 2026-10-25) ·
On the furnace label: 0.80 older, 0.90–0.98 condensing.
Gas furnace costs less per year by
Electric resistance: $5,897.92 a year · Gas furnace: $1,222.75 a year, for 104.2 MMBtu of heat.
- Yearly heating load
- 104.2 MMBtu
- Electric resistance, $ per MMBtu
- $56.62
- Gas furnace, $ per MMBtu
- $11.74
- Electric resistance, per year
- $5,897.92
- Gas furnace, per year
- $1,222.75
- Difference per year (Gas furnace − Electric resistance)
- −$4,675.17
- Seasonal heat pump COP used
- 2.5
- Prices used
- electricity 19.3¢/kWh · gas $1.08/therm · propane $2.10/gal · oil $3.60/gal
- Heat pump, per year (for reference)
- $2,359.17
Cost by month, in season only
The yearly cost spread across the months using a typical heating degree-day pattern from NOAA 1991–2020 normals. Months outside the season show $0.
Estimate. Formula and sources are under “How it works”. Change any input; the result updates as you type.
2026 note: The federal 25C and 25D tax credits ended for installations after Dec 31, 2025. Our numbers use 2026 rules. State rebates, HEAR/HOMES programs and utility programs may still apply.
Worked example
Worked example: 2,000 sq ft in Illinois
A 2,000 sq ft house with average insulation in Illinois needs about 104.2 MMBtu of heat a year (6,200 heating degree-days). At $1.08/therm in a 92% furnace, gas delivers that heat at $11.74 per MMBtu; resistance heat at 19.3¢/kWh costs $56.62, and a heat pump at seasonal COP 2.5 (zone 5) costs $22.65. The year comes to $1,222.75 on gas, $5,897.92 on resistance heat and $2,359.17 on a heat pump. Gas is the cheapest to run here, by $1,136.42 a year over a heat pump.
Load = sq ft × 0.35 × heating degree-days × 24 ÷ 1,000,000. Gas $/MMBtu = $/therm ÷ 0.1 ÷ 0.92. Resistance $/MMBtu = $/kWh × 293.07. Heat pump = resistance ÷ COP.
What the numbers say
What the numbers say in Illinois
Low gas prices and a long winter make Illinois one of the harder places for a heat pump to beat a furnace on running cost. Gas costs $1.08/therm, 27% below the US average of $1.48/therm and the 11th-lowest price among the states, while electricity costs 19.3¢/kWh, 6% above the US average of 18.2¢/kWh. With 6,200 heating degree-days, 38% more than the US average of 4,500, the example house burns around 1,132 therms a year in a gas furnace, and climate zone 5 gives the heat pump a seasonal COP of 2.5.
The estimate lands on gas, by $1,136.42 a year. The rate at which a heat pump would match the furnace is 10.0¢/kWh; the state average is 19.3¢/kWh. The two figures sit far apart, so for a home that already has a working gas furnace, the case for a heat pump in Illinois rests on something other than the heating bill: cooling, comfort, or a plan to drop gas service altogether. Where both are in the picture, the heat pump vs furnace page compares them over the equipment's life.
Electric homes see the opposite picture. For the 17% on electricity, baseboard or electric-furnace heat costs 4.8 times what gas does per unit of heat at these prices, $5,897.92 a year for the example house, and a heat pump would bring that down to $2,359.17. That comparison, not gas against a heat pump, is the one worth running if your home has no gas line.
The survey's $606 a year is the average of all Illinois homes and fuels, so it comes in under the calculator's $1,222.75 for a 2,000 sq ft house. To bring the estimate closer to your home, enter your square footage and the price per therm from your gas bill with every charge included. With most of the state on gas, shrinking the load is the other lever: the thermostat setback and attic insulation calculators put a figure on it, and the furnace size page checks whether a replacement unit is oversized.
Questions
FAQ
Which is cheaper in Illinois, gas or electric heat?
Electric resistance heat is the most expensive of the three in Illinois: $5,897.92 a year for the 2,000 sq ft example, $4,675.17 more than gas. Between gas ($1,222.75) and a heat pump ($2,359.17), gas is cheaper here: $11.74 per MMBtu of heat against $22.65 for a heat pump at seasonal COP 2.5. These are estimates at 19.3¢/kWh and $1.08/therm; your bill's prices can change the answer.
How much gas does a furnace use in Illinois?
About 1,132 therms a year for a 2,000 sq ft house with average insulation and a 92% furnace, at Illinois's 6,200 heating degree-days. That averages 94 therms a month over 12 months, but almost all of it is burned in the heating months. At $1.08/therm, the year costs an estimated $1,222.75.
Electric furnace vs gas furnace cost in Illinois?
An electric furnace is resistance heat: every kWh gives 3,412 BTU. At 19.3¢/kWh, that heat costs $56.62 per MMBtu in Illinois, against $11.74 from a 92% gas furnace at $1.08/therm, 4.8 times as much. For the 2,000 sq ft example that's $5,897.92 a year against $1,222.75.
Will a heat pump lower my heating bill in Illinois if I have gas?
Not at the average prices. The estimate puts gas ahead by $1,136.42 a year for the example house, because gas here costs $1.08/therm and a heat pump only breaks even at an electricity rate of 10.0¢/kWh, against an average of 19.3¢/kWh. If your utility offers a special rate for electric heat, enter it above; anything well above the tie rate keeps gas cheaper.
My Illinois home has no gas line. What should I compare?
Electric resistance against a heat pump. At 19.3¢/kWh, baseboards or an electric furnace cost 4.8 times what gas costs per unit of heat, and the example house comes to $5,897.92 a year that way, against $2,359.17 with a heat pump at a seasonal COP of 2.5. Only 2% of homes here use one today; the heat pump payback page turns your quote and the yearly gap into years.
Bordering states
Nearby states
Same calculator, same house, each state's own prices and winter:
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