Free tool

Heater Running Cost Calculator

Heater power (watts)

Printed on the label or in the manual. Most plug-in space heaters are 1,500 W on high.

Hours used per day With a thermostat the element cycles off; use roughly 60–70% of the time it is switched on.

Days used per month

Months in your heating season

Currency

Electricity price (per kWh)

Whole heating season–

Per hour–

Per day–

Per month–

Energy per month–

Monthly saving if a 100 W heated blanket did the job–

Formula: watts ÷ 1,000 × hours × price per kWh. Figures are estimates — your bill also depends on thermostat cycling, standing charges and time-of-use tariffs.

Enter your heater’s wattage, how long you run it and your electricity price to see what it really costs per hour, per day, per month and across a whole winter.

Cut the number before you buy anything

Stop drafts first — a sealed room holds heat, so the thermostat cycles off sooner.
Match the heater type to the room — radiant heat for drafty spaces, oil-filled for closed bedrooms.
Heat yourself, not the room — a heated blanket or pad uses a fraction of the power.