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, $5,867.40 with electric resistance heat and $2,346.96 with a heat pump. At these prices gas is the cheapest of the three, $1,124.21 a year under a heat pump.
State data
What Illinois pays
- Electricity
- 19.2¢/kWhEIA Electric Power Monthly, table 5.6.A · EIA, July 2026 (data as of 2026-09-28)
- Natural gas
- $1.08/thermEIA, residential natural gas price ($/Mcf ÷ 10.37) · EIA 2025 annual average (data as of 2026-09-28)
- 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 19.2¢/kWh, Illinois has the 17th-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.
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: 19.2¢/kWh · Illinois · EIA, July 2026 · gas $1.08/therm (EIA 2025 annual) · 6,200 heating degree-days · climate zone 5 (data as of 2026-09-28) ·
On the furnace label: 0.80 older, 0.90–0.98 condensing.
Gas furnace costs less per year by
Electric resistance: $5,867.40 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
- $56.33
- Gas furnace, $ per MMBtu
- $11.74
- Electric resistance, per year
- $5,867.40
- Gas furnace, per year
- $1,222.75
- Difference per year (Gas furnace − Electric resistance)
- −$4,644.65
- Seasonal heat pump COP used
- 2.5
- Prices used
- electricity 19.2¢/kWh · gas $1.08/therm · propane $2.10/gal · oil $3.60/gal
- Heat pump, per year (for reference)
- $2,346.96
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 19.2¢/kWh costs $56.33, and a heat pump at seasonal COP 2.5 (zone 5) costs $22.53. The year comes to $1,222.75 on gas, $5,867.40 on resistance heat and $2,346.96 on a heat pump. Gas is the cheapest to run here, by $1,124.21 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.
Questions
FAQ
Which is cheaper in Illinois, gas or electric heat?
Electric resistance heat is the most expensive of the three in Illinois: $5,867.40 a year for the 2,000 sq ft example, $4,644.65 more than gas. Between gas ($1,222.75) and a heat pump ($2,346.96), gas is cheaper here: $11.74 per MMBtu of heat against $22.53 for a heat pump at seasonal COP 2.5. These are estimates at 19.2¢/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 19.2¢/kWh, that heat costs $56.33 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 $5,867.40 a year against $1,222.75.
Bordering states
Nearby states
Same calculator, same house, each state's own prices and winter:
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