See what a space heater costs per hour, per day and per month on your electricity rate – and whether heating one room beats turning up the whole house.
By TanLabs Editorial Team · Reviewed: page results cross-checked against the free spreadsheet · Last updated · Runs in your browser – nothing you type is sent anywhere
With heater wattage 1,500 W, share of time it is actually heating 100%, hours per day 8, days per month 30, number of heaters 1, electricity price 17 ¢ per kWh, months you use it 4:
About $61.20 a month ($2.04 a day)
$0.26 per hour · 360 kWh a month · 4-month season: $244.80
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kWh per hour = watts × share of time heating ÷ 1,000 × number of heaters. Cost per hour = kWh per hour × price per kWh. Per day = per hour × hours; per month = per day × days; season = per month × months.
Formula source: kWh = watts × hours ÷ 1,000; cost = kWh × residential electricity price (EIA). U.S. EIA – energy conversion calculators · U.S. EIA – average residential electricity price by state
Written and checked by the TanLabs Editorial Team · Last updated
At 17¢ per kWh, 30 days a month, 4-month season:
| Use at 17¢ per kWh | Per hour | Per day | Per month | 4-month season |
|---|---|---|---|---|
| Low setting, 4 h a day | $0.13 | $0.51 | $15.30 | $61.20 |
| High, 4 h a day | $0.26 | $1.02 | $30.60 | $122.40 |
| High, 8 h a day (home office) | $0.26 | $2.04 | $61.20 | $244.80 |
| High with thermostat cycling 50%, 8 h | $0.13 | $1.02 | $30.60 | $122.40 |
| High, 24 h a day | $0.26 | $6.12 | $183.60 | $734.40 |
| Two heaters on high, 8 h | $0.51 | $4.08 | $122.40 | $489.60 |
One heater on high in a home office for 8 hours a day costs about $61 a month. Running it around the clock costs three times as much – often more than heating the whole house with gas.
1.5 kWh per hour. At 17¢ per kWh that is about 26¢ an hour, or about $2 for an 8-hour day.
Yes. Low is often 750 W, half the cost of high. A heater with a thermostat also switches off when the room is warm, which is what the "share of time heating" input models.
Not per watt – all electric resistance heaters turn 1 kWh into 3,412 Btu of heat. Oil-filled models hold heat and cycle off more, which can lower the share of time they draw power.
It can be if you heat one room and turn the house thermostat down. Heating the whole house with several space heaters usually costs more than a gas furnace or heat pump.
A 1,500 W heater uses 1.5 kWh per hour on high, or 12 kWh in an 8-hour day.
Many fire departments advise against it. If you do, use a heater with tip-over and overheat shut-off and keep a three-foot clear zone.
Sources: U.S. EIA – average residential electricity price by state · U.S. EIA – energy conversion calculators