Space Heater Cost Calculator
Enter your heater's wattage and usage to see your exact running cost.
Calculate Your Space Heater Cost
How to Calculate Space Heater Running Cost
Divide your heater's wattage by 1,000 to get kilowatt-hours per hour (kWh/hr). Then multiply by your electricity rate. For example: a 1500W heater ÷ 1,000 = 1.5 kWh/hr. At the US average of 18.44¢/kWh, that's 1.5 × $0.1844 = $0.28 per hour.
To find your monthly cost, multiply the hourly cost by daily hours and days used. Running 8 hrs/day for 30 days is 360 kWh: 360 × $0.1844 = about $66.38/month. That assumes the heater runs at full wattage the whole time, so a thermostat will bring it in lower. Rates vary a great deal by state — from 12.35¢/kWh in Idaho to 52¢/kWh in Hawaii — so check your utility bill for your actual rate. For a wattage-by-wattage breakdown, see space heater cost per hour across all common models. For broader context on what electric heat costs across the home, our electric heating cost guide covers whole-home electric systems.
Space Heater Cost — FAQs
Related Pages
Space Heaters Worth the Running Cost
Once you know what your heater costs per hour, the question is whether a different unit would run fewer of those hours. These four are picked on thermostat accuracy, timers and wattage steps rather than on heat output claims.
Dual heating system, adjustable thermostat, 12-hour timer. The combination means it spends less of each hour at full draw than a heater with a simple on/off dial.
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Oscillation avoids the cold corners that make people turn the dial up. Even distribution is an indirect saving: the thermostat satisfies sooner.
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Console-style ceramic with widespread oscillation and two heat settings. No resistance heater is more efficient than another, so a cheaper unit with a working thermostat costs the same to run as an expensive one.
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Permanently sealed oil, never needs refilling. Best suited to a room you heat for hours at a time rather than short bursts.
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