How much does a 1,500-watt heater cost per hour?

A 1,500-watt heater uses 1.5 kWh each hour it runs on full power. At $0.17 per kWh that is about $0.26 an hour. Multiply your own price per kWh by 1.5 to get the hourly cost on your tariff.

Is a space heater cheaper than central heating?

It depends on how much you heat. Warming a single occupied room with a space heater can beat heating the whole house centrally. But keeping several rooms warm with plug-in heaters usually costs more than efficient central heating, especially a heat pump, which delivers more than one unit of heat per unit of electricity. Compare on your own rate and usage.

Do oil-filled radiators use less electricity?

No — at the same wattage they use the same electricity as any other resistive heater. An oil-filled radiator holds heat and cycles more gently, which can feel steadier and let its thermostat keep it off more of the time, but watt for watt it is not cheaper. Power rating and run hours set the cost, not the heater's style.

How do I cut the cost of running a space heater?

Cut power, hours, or heated space. Run a lower setting or use a thermostat so it is not on full all the time, heat only the room you are in, close the door, and switch off or use a timer when you leave. Cutting the hours in half roughly halves the cost — the maths is that direct.

How Much Does a Space Heater Cost to Run?

Published 5/20/2026 · 5 min read · Real-estate calculators

Marco Bianchi — Home, DIY & motoring writer at OneKitly

Renovation · Materials

Checked against 2 sources

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In short

Running cost is the heater's power in kilowatts times the hours it runs times your electricity price per kWh. A 1,500-watt (1.5 kW) space heater running 5 hours a day uses 7.5 kWh per day. At $0.17 per kWh that is about $1.28 a day, roughly $38 a month, and near $460 over a five-month heating season. Because electric heaters are essentially 100% efficient, all the wattage becomes heat — so cost scales directly with power and hours, and the only real levers are running it less, at a lower setting, or heating a smaller space.

A red column radiator against a wall of the same colour. — Jan van der Wolf · Pexels · Pexels

Multiply the heater's kilowatts by hours used and your price per kWh — a 1.5 kW heater for 5 hours a day adds up fast at typical tariffs.

The formula behind every heating bill

An electric heater's cost is one of the most honest sums in the home, because there is no efficiency loss to argue about. A resistive heater turns essentially all its electrical power into heat, so every watt on the label is a watt you pay for. The whole cost is kilowatts times hours times price per kWh, and nothing hides in between. A 1.5 kW heater run for 5 hours uses 7.5 kWh, and at $0.17 per kWh that day costs about $1.28.

The reason the totals surprise people is that heaters are among the highest-wattage devices in the house, and they run for hours. A single 1.5 kW heater kept on through the evening can quietly out-spend a fridge that runs all month. Multiply the daily figure by a heating season and the numbers become real money — which is exactly why it pays to check them before you leave a heater running in an empty room.

Watts, settings, and the myth of the cheap heater

Every resistive space heater of the same wattage costs the same to run, whatever its shape or marketing. A fan heater, an oil-filled radiator, and a bar heater all rated 1.5 kW consume the same 1.5 kWh per hour on full power. What differs is comfort and control: an oil-filled radiator holds heat and cycles gently, a fan heater warms a spot fast, but neither is cheaper per unit of heat. Claims of a heater that gives more warmth for less electricity should be treated with caution, because physics fixes the ceiling at one watt of heat per watt of power.

The genuine savings come from three levers. Use a lower power setting or a thermostat so the heater is not on full the whole time; heat only the room you occupy rather than the whole house; and cut the hours by switching off when you leave or using a timer. A heat pump is the one exception that beats 100% — it moves heat rather than making it — but among plain electric heaters, less power and fewer hours are the only ways down.

Turning the daily number into a season

A daily cost feels small; a season does not. Take the $1.28 a day from a 1.5 kW heater at 5 hours and $0.17 per kWh: across a 30-day month that is about $38, and across a five-month heating season roughly $190 — for one heater in one room. Add a second heater, or leave the first on longer, and the seasonal figure climbs in step. Seeing the season total, not the daily one, is what changes behaviour.

Your tariff is the other big variable, and it moves the answer as much as the heater does. A time-of-use plan that charges more in the evening peak can double the cost of the same heating hours, so shifting use to off-peak, or comparing a space heater against central heating on your actual rate, is worth doing before winter. Run your own wattage, hours, and price through the calculator to get a figure that matches your home rather than a magazine average.

Worked with our own calculator

Appliance running cost calculator

Given

Power (W): 4,000
Hours per day: 6
Price per kWh: $0.40

Result

Daily cost: $9.60
Monthly cost: $288.00
Yearly cost: $3,504.00

These figures are produced by the calculator below, not typed in by hand — they are recomputed whenever the tool changes.

Run it on your own figures →

Frequently asked questions

How much does a 1,500-watt heater cost per hour?: A 1,500-watt heater uses 1.5 kWh each hour it runs on full power. At $0.17 per kWh that is about $0.26 an hour. Multiply your own price per kWh by 1.5 to get the hourly cost on your tariff.
Is a space heater cheaper than central heating?: It depends on how much you heat. Warming a single occupied room with a space heater can beat heating the whole house centrally. But keeping several rooms warm with plug-in heaters usually costs more than efficient central heating, especially a heat pump, which delivers more than one unit of heat per unit of electricity. Compare on your own rate and usage.
Do oil-filled radiators use less electricity?: No — at the same wattage they use the same electricity as any other resistive heater. An oil-filled radiator holds heat and cycles more gently, which can feel steadier and let its thermostat keep it off more of the time, but watt for watt it is not cheaper. Power rating and run hours set the cost, not the heater's style.
How do I cut the cost of running a space heater?: Cut power, hours, or heated space. Run a lower setting or use a thermostat so it is not on full all the time, heat only the room you are in, close the door, and switch off or use a timer when you leave. Cutting the hours in half roughly halves the cost — the maths is that direct.

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