Space Heater Cost Calculator

Frequently Asked Questions

How much does it cost to run a space heater?

Cost = wattage ÷ 1,000 × hours × your electricity rate. A standard 1,500 W space heater running 8 hours a day at $0.17/kWh costs about $2.04 per day and $61 per month. This calculator does the exact math for your wattage, hours, and rate.

Do space heaters use a lot of electricity?

Yes — a space heater is one of the most power-hungry appliances in a home. A 1,500 W heater draws as much power as roughly 100 LED light bulbs or 15 old incandescent bulbs. Running one 8 hours a day adds about 360 kWh to your monthly bill — roughly a 40% increase for an average US household.

How many watts does a space heater use?

Most portable space heaters use 750–1,500 watts: 750 W on low/eco mode, 1,000 W on medium, 1,500 W on high. The label on the back of your heater shows its exact wattage — check there if you are unsure.

How many BTU is a space heater?

A 1,500 W space heater produces about 5,120 BTU per hour (watts × 3.412 = BTU/h). A 750 W heater produces about 2,560 BTU/h. That is enough to warm one room, not a whole house — which is the point of zone heating.

Does a space heater save money?

Only if you use it for zone heating: turn down the central thermostat and heat just the room you are in. If the space heater runs on top of full central heating, it only adds to your bill. The biggest savings come from dropping the whole-house thermostat 5–10°F and heating one occupied room.

Is it expensive to run a space heater all day?

A 1,500 W heater running 24 hours costs about $6.12 per day at $0.17/kWh — over $180 a month. Never run a space heater unattended or overnight: besides the cost, it is a fire risk. Use a timer or a model with an auto-shutoff.

Is this space heater cost calculator free?

Yes — completely free, no signup, no downloads. It runs 100% in your browser, so your answers never leave your device.