Running a 1,500-watt space heater 8 hours a day in Tennessee costs about $50.38 a month — $0.21 an hour on full power at Tennessee's average 13.80¢/kWh.
At 13.80¢/kWh — Tennessee average, Jan–Aug 2026 (EIA). That is 24% below the U.S. average of 18.19¢.
| Period | kWh | Cost |
|---|---|---|
| Per hour of use | 1.5 | $0.21 |
| Per day | 12 | $1.66 |
| Per month | 365 | $50.38 |
| Per season (7 mo) | 2,555 | $353 |
Normal mean temperature (NOAA, population-weighted). Highlighted months average below 60°F.
| Heat source | $ per million Btu | This much heat |
|---|---|---|
| Gas furnace, 95% AFUE | $12.03 | $14.99 |
| Gas furnace, 80% AFUE | $14.29 | $17.80 |
| Heat pump (ENERGY STAR avg) | $16.35 | $20.37 |
| Propane furnace, 95% AFUE | $37.05 | $46.15 |
| Space heater / baseboard | $40.45 | $50.38 |
In Tennessee resistance heat costs 3.4× as much as gas heat from a 95% furnace. A space heater only saves money when it lets you turn the whole-house thermostat down several degrees and heat just the room you're in. A heat pump delivers the same heat for about $20.37 a month.
| Heater | Per hour | 8 h/day, month | 24 h/day, month | Season (7 mo, 8 h) |
|---|---|---|---|---|
| 750 W | $0.10 | $25.19 | $75.56 | $176 |
| 900 W | $0.12 | $30.23 | $90.68 | $212 |
| 1,500 W | $0.21 | $50.38 | $151.13 | $353 |
1.5 kW × 8 h = 12 kWh a day; × 30.42 days = 365 kWh a month; × 13.80¢ (Tennessee average, Jan–Aug 2026, EIA) = $50.38.
Because resistance heat costs 3.4× as much as gas heat in Tennessee, a space heater saves money only if it lets you turn the whole-house thermostat down and heat just the room you're in. If your home heats with electric baseboards or furnace strips, a space heater costs the same per Btu — the saving comes only from heating fewer rooms.
The average Tennessee home used 1,217 kWh a month in 2025 (EIA); this heater adds 30% to that while it runs.
The full method, material data and tips are on the main space heater cost calculator page.