Three tested scenarios
| Scenario | Assumptions | Annual energy | Annual cost |
|---|---|---|---|
| Occasional-use example | 1,500 W, 1 h/day, 3 days/week, 100% duty; 0 W standby; $0.18/kWh | 234.643 kWh | $42.24 |
| Regular-use example | 1,500 W, 3 h/day, 5 days/week, 100% duty; 0 W standby; $0.18/kWh | 1,173.214 kWh | $211.18 |
| Daily extended-use example | 1,500 W, 6 h/day, 7 days/week, 100% duty; 0 W standby; $0.18/kWh | 3,285.000 kWh | $591.30 |
Examples assume full power while scheduled and a rate of $0.18/kWh.
How the estimate works
If a thermostat cycles the heating element, a measured multi-hour average or a representative duty cycle improves the estimate. Fan-only modes draw differently.
What changes heater cost?
- Wattage setting, runtime, thermostat setpoint, and cycling.
- Outdoor temperature, insulation, air leakage, and room size.
- Whether the heater replaces or merely supplements another heating system.
Safety comes first
Cost alone cannot determine the safest heating choice. Follow the product instructions and current safety guidance before comparing operating costs.
Measure carefully
High-power heaters can exceed the rating of some consumer meters and plugs. Check device ratings and instructions before connecting any measurement equipment. When in doubt, use the nameplate wattage and consult a qualified professional.
Related: methodology · accuracy guide · all sources
Last reviewed: August 14, 2026