Space Heater Cost Calculator
See what a space heater actually adds to your bill — by the day, by the month, and across a whole heating season.
Estimate assumes the heater draws full wattage for the hours entered. Thermostatic models cycle on and off to hold a temperature, so actual cost is often somewhat lower than this.
How this is calculated
daily cost = kWh used × rate per kWh
seasonal cost = daily cost × days used
Worked example: a 1500W heater on high, run 6 hours a day at $0.17/kWh: (1500 ÷ 1000) × 6 = 9 kWh/day, × $0.17 ≈ $1.53/day — about $46/month, or roughly $138 across a 90-day winter.
Frequently asked questions
How much does it cost to run a space heater all winter?
Set "days used this season" to your expected heating season length (90 is a reasonable default for a typical winter) and the calculator adds up your daily cost across the whole season automatically.
Is a space heater cheaper than central heating?
It depends on how much of your home you're heating. A space heater can be cheaper if you're only heating one room you're actually in, since central heating warms the whole house. Heating your whole home with only space heaters is usually more expensive than a central system.
Does "low" vs "high" setting really make a difference?
Yes — most portable heaters run at 750W on low and 1500W on high, so switching from high to low roughly halves your running cost for the same amount of time.
How much electricity does a space heater use per hour?
A 1500W heater uses 1.5 kWh per hour it runs at full power; at the 2026 U.S. average rate of about $0.17/kWh, that's roughly $0.26 per hour. Enter your own wattage, hours, and rate above for an exact number — the currency selector also lets you switch the displayed symbol if you're outside the U.S.