Calculate exactly what your oil-filled radiator costs to run per hour, day, and month, at the current US average electricity rate or your own.
An oil-filled radiator is an electric resistance heater like any other: divide wattage by 1,000 to get kWh per hour, then multiply by your electricity rate. For a 1,500W oil heater at 18.44¢/kWh: 1.5 kWh × $0.1844 = $0.28 per hour at full power. Run it 8 hrs/day for 30 days and that is 360 kWh, or about $66/month.
What the sealed thermal oil changes is when the heat arrives, not how much electricity it takes to make it. The oil stores heat and gives it back for 30–60 minutes after the element switches off, so the radiator warms and cools gently instead of in bursts. That is a comfort difference, not an energy saving: on 1,500W an oil radiator draws the same 1,500W as a 1,500W ceramic or infrared heater. Every thermostatic heater switches off for part of each hour once the room is up to temperature, and how large that share is comes down to how quickly your room loses heat — insulation, glazing, outdoor temperature — not to the type of heater. The figures on this page assume continuous running at rated wattage, so a real bill normally lands below them.
For a detailed wattage-by-wattage breakdown, see our 1500-watt heater cost guide. To compare oil heaters against other types, check infrared vs oil heater cost or our oil vs ceramic heater comparison.
| Wattage | Cost/Hour | Cost/Day (8 hrs) | Cost/Month | kWh/Month |
|---|---|---|---|---|
| 700W | $0.13 | $1.03 | $30.98 | 168 kWh |
| 1,000W | $0.18 | $1.48 | $44.26 | 240 kWh |
| 1,500W | $0.28 | $2.21 | $66.38 | 360 kWh |
| 2,000W | $0.37 | $2.95 | $88.51 | 480 kWh |
US average 18.44¢/kWh (EIA Electric Power Monthly, May 2026). 8 hrs/day, 30 days/month, at rated wattage throughout. A thermostat that switches the heater off part of each hour lowers all four columns together.