How much does it cost to run a space heater?

The formula

Find the heater's wattage (on the label or box) and your electricity price per kWh (on your bill). Divide the watts by 1,000 and multiply by your price. That's the cost per hour at full power.

Multiply by the hours you use it each day for the daily cost, then by 30 for a rough monthly figure.

Worked examples

• 1,500W heater, 4 hours a day at 0.25/kWh: 1.5 × 0.25 × 4 = 1.50 a day, about 45 a month
• 800W heater (RapidHeat High), same use: 0.8 × 0.25 × 4 = 0.80 a day, about 24 a month
• 400W heater (RapidHeat Low), same use: 0.4 × 0.25 × 4 = 0.40 a day, about 12 a month

Why your bill may be lower than the maths

These figures assume the heater runs at full power the whole time. With a thermostat, it cycles off once the room is warm, so in a closed, well-insulated room actual use is often lower. In a draughty room it will be closer to the full figure.

Space heater vs central heating

Central heating heats every room; a space heater heats one. If you only use one or two rooms in the evening, turning the main heating down and heating just that room can cost less overall, even when electricity costs more per kWh than gas. Compare your own prices to be sure.

Ways to cut the cost

• Pick a lower-wattage heater matched to your room size
• Use the thermostat and the low setting once warm
• Use a timer so it never runs when you're not there
• Close doors and curtains, and block draughts

Why RapidHeat fits

• Plugs straight into a wall outlet, so there's nothing to install
• Ceramic heating with 400W and 800W modes
• Digital thermostat, remote control and timer
• Quiet at around 45 dB
• Overheat protection and automatic shut-off
• Suits rooms up to about 250 sq ft (≈23 m²)

How many heaters for your room?

A rough guide for topping up a home that has some heating. Cold, high-ceilinged or poorly insulated rooms may need more.

What it costs to run

Maximum cost at full power, for common electricity prices per kWh in your own currency. With the thermostat cycling off once the room is warm, real costs are often lower. Try the energy cost calculator with your exact price.

Who RapidHeat is not for

We'd rather you buy the right heater than return the wrong one. RapidHeat isn't the best choice for:

• Heating a whole house or open-plan floor on its own
• Large rooms over about 250 sq ft (≈23 m²) with just one unit (use two or more)
• Bathrooms or anywhere it could get splashed with water
• People who want silent, fan-free heat (try an oil-filled radiator)

Common questions