Homes in Illinois paid an average of 19.22¢ per kWh in July 2026, close to the U.S. average of 18.31¢. Prices are up 11.6% from 17.22¢ a year earlier.
A standard 1,500 W space heater on high costs about $0.29 an hour here, or $2.31 for an 8-hour evening. Every evening for a month adds about $69.19. On the 900 W low setting the same month is about $41.52. Four hours a day on high is about $34.60. That is $3.28 a month more than the same heater costs at the U.S. average price.
Work out your cost in Illinois
Change any number. The price per kWh is printed on your electric bill.
Starts at Illinois's average residential price, 19.22¢/kWh. Source: U.S. EIA, Electric Power Monthly, Table 5.6.A (residential sector), July 2026 (released September 24, 2026). Month is 30 days; year is 12 such months.
Monthly cost by setting and hours
| Use | Illinois, July 202619.22¢/kWh | Illinois, July 202517.22¢/kWh | U.S. average18.31¢/kWh |
|---|---|---|---|
| Low, 900 W, 4 h a day108 kWh a month | $20.76 | $18.60 | $19.77 |
| High, 1,500 W, 4 h a day180 kWh a month | $34.60 | $31.00 | $32.96 |
| Low, 900 W, 8 h a day216 kWh a month | $41.52 | $37.20 | $39.55 |
| High, 1,500 W, 8 h a day360 kWh a month | $69.19 | $61.99 | $65.92 |
| High, 1,500 W, 24 h a day1,080 kWh a month | $208 | $186 | $198 |
Cost per 30-day month. EIA's state figure is the average price residential customers paid (revenue ÷ kWh sold), so it includes delivery charges. Your own utility's rate may differ.
Because prices were up 11.6% from a year earlier, the same 8-hour month on high went from $61.99 to $69.19. At the U.S. average it is $65.92.
What a whole winter costs
Most heaters only run part of the year. Four hours a day on high from November through March (150 days) uses 900 kWh, about $173 in Illinois at today's average price. The same season on low is about $104.
Ways to pay less
- Turn the central thermostat down while you use it. A space heater only saves money if it lets you heat one room instead of the whole home. DOE estimates up to 10% a year in heating savings from setting the thermostat back 7–10°F for 8 hours a day.
- Drop to low once the room is warm. 900 W instead of 1,500 W saves about $27.68 a month at 8 hours a day in Illinois.
- Use the timer. Left on around the clock, a heater on high would cost about $208 a month in Illinois. Many models have an auto-off timer.
- If electric heat is your main heat, price a heat pump. DOE says heat pumps can cut the electricity used for heating by about 50% compared with resistance heaters like space heaters and baseboards.
Safety. Plug space heaters straight into a wall outlet, never an extension cord or power strip, and keep them at least 3 feet from beds, curtains and furniture (CPSC).
More on heater types and wattage: what a space heater costs to run. A cheaper way to stay warm in bed: electric blanket costs.
Nearby states
Of the 5 states in the East North Central census division, Illinois is 3rd most expensive for the same heater at 8 hours a day.
Questions
How much does it cost to run a space heater for an hour in Illinois?
A 1,500 W heater on high uses 1.5 kWh per hour. At Illinois's average residential price of 19.22¢/kWh (July 2026, U.S. EIA) that's about $0.29 per hour; on a 900 W low setting it's about $0.17.
How much does it cost to run a space heater all night in Illinois?
Eight hours on high is 12 kWh, about $2.31 a night or $69.19 over a 30-day month. Safety agencies (CPSC) advise not to leave a space heater running while you sleep; an electric blanket (about 100 W) costs roughly $0.15 for the same 8 hours.
How much does a space heater add to an electric bill in Illinois?
Running a 1,500 W heater 4 hours a day adds about $34.60 a month; 8 hours a day adds about $69.19; around the clock it's about $208. Use the calculator above with the rate from your own bill.
Has electricity gotten more expensive in Illinois?
EIA's average residential price in Illinois was 19.22¢/kWh in July 2026, up 11.6% from 17.22¢ in July 2025. The U.S. average moved from 17.45¢ to 18.31¢ (+4.9%).
Sources
- U.S. EIA, Electric Power Monthly, Table 5.6.A (residential sector), July 2026 and July 2025 (released September 24, 2026). Used for: Illinois and U.S. average residential prices
- U.S. CPSC: Staff Assessment on Portable Electric Heaters (Feb 2023). Used for: Plug-in heaters top out at 1,500 W
- Lasko 754200 ceramic heater, manufacturer specifications. Used for: Typical settings: 900 W low, 1,500 W high
- U.S. DOE: Energy Saver Guide (2022). Used for: Up to 10% heating savings from a 7–10°F setback; heat pumps use about 50% less electricity than resistance heat
- U.S. CPSC: Space heater safety warning. Used for: 3-foot clearance, wall outlet only, don't run while sleeping
Math: cost = watts × hours ÷ 1,000 × price per kWh; a month is 30 days. The state table is also available as a CSV, free to reuse with credit to WattCost.