Space heater cost per hour, at your rate.

Short answer

Cost per hour = watts / 1000 x your price per kWh. A 1,500 W heater at $0.15 per kWh costs $0.225 per hour running continuously, $1.80 for 8 hours, and $54.00 over 30 days of 8-hour days.

Worked example

1,500 W = 1.5 kW. At $0.15 per kWh and full power: 1.5 x 0.15 = $0.225 per hour, x 8 hours = $1.80 per day, x 30 days = $54.00 for 360 kWh. If the thermostat keeps it on 50% of the time, the same period costs $27.00. At full power it gives off 1,500 x 3.412 = 5,118 BTU/h.

Formula, assumptions and sources

Energy (kWh) = watts / 1000 x hours x duty cycle; cost = kWh x price. Natural Resources Canada states that electric space heaters produce one unit of heat for every unit of electricity, so they are 100 percent efficient at the end use, but not necessarily the cheapest way to heat; its example is that geothermal heat pumps deliver three units of heat per unit of electricity. Heat output uses the EIA conversion of 1 kWh = 3,412 Btu (so 3.412 Btu/h per watt). The price you enter should include delivery, taxes and any time-of-use rate; the tool does not look up tariffs. Heater safety: CPSC says portable electric heaters are high-wattage appliances, to place them on a stable level surface away from combustibles and never to power one with an extension cord or power strip.

Source: Natural Resources Canada, Electric heaters (opened 2026-10-08)

Source: U.S. Energy Information Administration, British thermal units (Btu) (opened 2026-10-08)

Source: U.S. Consumer Product Safety Commission, Reducing Fire Hazards for Portable Electric Heaters (opened 2026-10-08)

Safety and limits

This is a planning aid, not professional advice. Electrical and HVAC work can cause fire, shock and carbon monoxide hazards; have a licensed professional size, install and inspect equipment.

FAQ

How much does a 1,500 watt space heater cost to run per hour?

At $0.15 per kWh, $0.225 per hour at full power. Multiply 1.5 kW by your own price per kWh.

Does a thermostat lower the cost?

Yes, in proportion to the time the heater is off. At a 50% duty cycle the 30-day example drops from $54.00 to $27.00.

Is an electric space heater the cheapest way to heat?

NRCan says electric heaters are 100 percent efficient at the end use but not necessarily the most efficient choice; its example is that geothermal heat pumps deliver three units of heat per unit of electricity. Compare options with the heating cost comparison tool.