Space Heater Running Cost Calculator
Enter your heater's wattage and usage hours to see exactly what it costs to run. Works for all types — ceramic, oil-filled, infrared, panel heaters, and fan heaters.
Last verified: April 29, 2026
Per hour
$0.26
Per day
$2.09
Per month
$63
Per year
$753
- kWh per hour
- 1.5 kWh
- kWh per day
- 12.0 kWh
- kWh per month
- 360 kWh
- Annual addition to bill
- 4,320 kWh
Electric heaters are 100% efficient — all power becomes heat. Costs are exact, not estimated.
How this is calculated
Electric heaters convert 100% of electricity into heat. The formula is straightforward: multiply wattage by hours to get energy, then multiply by your electricity rate.
kWh per hour = Watts ÷ 1,000
Cost per hour = kWh × Rate
Cost per day = Cost/hr × Hours/day
Cost per month= Cost/day × Days/month
Cost per year = Cost/month × 12
Example (1,500W, 8 hrs/day, $0.1745/kWh):
kWh/hr = 1,500 ÷ 1,000 = 1.5 kWh
Cost/hr = 1.5 × $0.1745 = $0.262
Cost/day = $0.262 × 8 = $2.09
Cost/month = $2.09 × 30 = $62.82
Cost/year = $62.82 × 12 = $753Assumptions
- Heater runs at constant wattage — thermostatic models may cycle on/off (actual use may be lower)
- "Days per month" is used to calculate monthly and annual figures
- Annual cost assumes same usage every month — adjust for seasonal use
- No standby power assumed (most heaters draw 0W when off)
Cost comparison by wattage
| Heater type / Wattage | Cost/hr | Cost/day (8hr) | Cost/month |
|---|---|---|---|
| Mini ceramic / panel (400W) | 30.07 | $0.56 | $16.75 |
| Small heater (low) (750W) | 30.13 | $1.05 | $31.41 |
| Medium heater (1,000W) | 30.17 | $1.40 | $41.88 |
| Standard heater (high) (1,500W) | 30.26 | $2.09 | $62.82 |
| Large heater (2,000W) | 30.35 | $2.79 | $83.76 |
| Workshop / industrial (3,000W) | 30.52 | $4.19 | $125.64 |
US average $0.1745/kWh (EIA, 2026-04-27). 8 hours/day, 30 days/month.
Frequently asked questions
How much does it cost to run a 1500W space heater? ▾
At the US average rate of $0.1745/kWh, a 1500W heater costs about $0.26 per hour, $2.09 per day (8 hours), $62.82 per month, or $753 per year if used year-round. Most people only use space heaters for a few months, so actual annual costs are lower.
Is a space heater cheaper than central heating? ▾
It depends. If you only need to heat one room, a space heater can be cheaper than heating your whole home. But if you use multiple heaters, or heat large areas, central heating (especially gas or heat pump) is usually more economical. Space heaters are 100% efficient electrically — all power becomes heat — but electricity is typically more expensive than gas per BTU.
What wattage is most common? ▾
Most portable space heaters have two settings: 750W (low) and 1,500W (high). Oil-filled radiator heaters range from 600–1,500W. Infrared heaters are typically 300–1,500W. Mini ceramic heaters can be as low as 200W. Industrial or workshop heaters can reach 3,000–5,000W.
Does a space heater on low use half the electricity? ▾
Yes — most heaters with a 750W/1500W switch use exactly half the electricity on low. However, some smart heaters use variable power (e.g., cycling on/off at full power) rather than truly halving the wattage. Check your heater's specs.
Can I reduce space heater running costs? ▾
Yes. Use a timer or smart plug to avoid running it while sleeping or out. Insulate the room better. Use the lower wattage setting when possible. Position the heater near where people sit, not in the centre of the room. A programmable thermostat can also help prevent overheating.
Sources
- U.S. EIA — Electric Power Monthly — US average residential electricity rate ($0.1745/kWh) (last checked 2026-04-29)
- U.S. Department of Energy — Space Heaters — Space heater efficiency and cost guidance (last checked 2026-04-29)