Calculate your cost
Start with the example below, then replace the wattage, daily runtime, and rate with the numbers for your space heater.
This setup uses about 225 kWh in a 30-day month.
Please enter valid values within the ranges shown.
| Schedule | Hours/day | Cost/month |
|---|---|---|
| Half runtime | 2.5 | $21.18 |
| Page example | 5 | $42.37 |
| Longer runtime | 7.5 | $63.55 |
Same 1,500-watt input and 18.83¢/kWh rate; only runtime changes.
Formula for the page example
1.5 kW × 5 hr × $0.1883 = $1.41 per day
Convert watts to kilowatts, multiply by the active hours used each day, then multiply by the electricity price in dollars per kWh. Multiply the daily result by 30 for the monthly estimate shown above.
How to read this estimate
At full heat, many plug-in space heaters draw close to the limit of a standard household outlet. The cost adds up when that heating element stays active for several hours a day, even if the heater itself is small.
Use this as a baseline until you can check the label or measure the space heater directly. Model, settings, condition, climate, and household routine can all change the result.
What changes the cost?
- 01
High, low, or thermostat-controlled heat setting
- 02
Room insulation, drafts, and outdoor temperature
- 03
Daily runtime and whether the heater cycles off
Ways to spend less
- Heat the occupied room and keep doors closed.
- Use the thermostat instead of leaving the heater on continuously.
- Stop drafts around doors and windows before increasing the setting.