Space Heater Cost Calculator
What a space heater really costs at your electricity rate — per hour, day, month, and whole season. Spoiler: heater style (ceramic, oil-filled, infrared) changes nothing; watts × hours × your rate is the whole story.
—per hour
—per day
—per 30-day month
—5-month season
Thermostat cycling: heaters click off once the room is warm. Real cost is often 50–75% of these numbers if you use the thermostat instead of running flat-out.
| Setting | Per hour @18¢ | 8 h/day month | Season (5 mo) |
|---|---|---|---|
| 500 W | $0.09 | $21.60 | $108 |
| 750 W | $0.14 | $32.40 | $162 |
| 1,000 W | $0.18 | $43.20 | $216 |
| 1,500 W | $0.27 | $64.80 | $324 |
The math (it's short)
kWh = watts ÷ 1,000 × hours · Cost = kWh × your rate
A 1,500 W heater burns 1.5 kWh every hour it's on. At 18¢: 1.5 × $0.18 = $0.27/hour. Eight hours = 12 kWh = $2.16. A month of that = $65. A five-month season = $324.
Things sellers won't tell you
- All 1,500 W heaters cost the same to run. Ceramic, oil-filled, infrared, fan — resistance heat is resistance heat. Marketing about "efficient infrared" is about where heat lands, not less cost per hour.
- The only real efficiency play: heat the room you're in and turn the house thermostat down. The heater saves money only when it replaces whole-house heating.
- Extreme rates are brutal: the same heater costs ~$0.19/hr in North Dakota and ~$0.71/hr in Hawaii. Pick your rate above, don't trust a national average.
- Safety is free: 1,500 W draws 12.5 A — most of a 15 A circuit. Wall outlet directly, no power strips, 3 ft clearance, never unattended asleep. (CPSC / USFA guidance.)
Rate basis: U.S. EIA residential average ~18.2¢/kWh (2026 data). Formula is exact physics (1 kWh = 3,412 BTU); the cycling adjustment is the only estimate.