Enter any heater wattage to see the exact cost per hour, per day, and per month. Works for all heater types — oil, ceramic, infrared, fan, and more.
The formula is simple: divide your heater's wattage by 1,000 to get kilowatt-hours (kWh) per hour, then multiply by your electricity rate. For example, a 1,500W heater uses 1.5 kWh per hour. At the US average of 18.44¢/kWh, that's 1.5 × $0.1844 = $0.28 per hour.
This calculator works for any electric heater type — oil-filled radiators, ceramic heaters, infrared panels, fan heaters, and baseboard heaters. Cost per hour depends only on wattage and electricity rate, not on heater technology, and so does cost per month: all of them convert essentially all the electricity they draw into heat, so at the same wattage holding the same room at the same temperature they consume the same energy. Every thermostatic heater is switched off for part of each hour once the room is up to temperature, and how large that share is depends on the room's heat loss — insulation, glazing, outdoor temperature — not on which type of heater is sitting in it. The figures here assume rated wattage for every hour, so treat them as the ceiling.
For heater-specific versions of this calculator, try our oil heater cost calculator, ceramic heater cost calculator, or infrared heater cost calculator.
| Wattage | Cost/Hour | Cost/Day (4 hrs) | Cost/Day (8 hrs) | Cost/Month |
|---|---|---|---|---|
| 500W | $0.09 | $0.37 | $0.74 | $22.13 |
| 750W | $0.14 | $0.55 | $1.11 | $33.19 |
| 1,000W | $0.18 | $0.74 | $1.48 | $44.26 |
| 1,250W | $0.23 | $0.92 | $1.84 | $55.32 |
| 1,500W | $0.28 | $1.11 | $2.21 | $66.38 |
| 2,000W | $0.37 | $1.48 | $2.95 | $88.51 |
| 3,000W | $0.55 | $2.21 | $4.43 | $132.77 |
| 5,000W | $0.92 | $3.69 | $7.38 | $221.28 |
US average 18.44¢/kWh (EIA Electric Power Monthly, May 2026). Monthly column is 8 hrs/day for 30 days. Costs are for continuous running at rated wattage — a thermostat that holds the heater off for part of each hour lowers every column together, by an amount set by how fast the room loses heat rather than by the type of heater.