Space Heater Running Cost Calculator

How the math works

Running cost = (watts ÷ 1,000) × hours used × your rate per kWh. A 1,500W heater used for 4 hours consumes 6 kWh; at $0.17 per kWh that is $1.02 for the evening. There is no trick to it, and any heater claiming to break that formula is not telling the truth.

Recommended in this guide

The compact heater this guide keeps coming back to

RapidHeat is a hand-sized ceramic heater that plugs straight into a wall outlet, pushes out warm air in about a minute and switches itself off on a timer. It is built for warming one room properly, not a whole house.

• Warm in ~60 seconds
• Under 30 dB
• Auto shut-off & timer

Order from $59 Free USA shipping · 30-day money-back

So where do the savings come from?

Not from the heater using less electricity than physics allows — from heating less space. If your furnace or central system warms nine rooms so that one feels comfortable, you are paying for eight rooms nobody is in. Heating a single occupied room with a 1,500W unit is frequently cheaper than raising the thermostat for the whole house, particularly in shoulder-season weather when you only need a few hours of warmth in the evening.

Four ways to cut the number above

• Use the thermostat — set a comfortable temperature rather than running full blast.
• Use the timer so it never runs while you are asleep or out.
• Close the door and block the draft underneath it.
• Turn the central thermostat down while the room heater is on, not as well as.

Want the full picture? Compare RapidHeat with central heating and radiators or see bundle pricing.