What does an oil-filled radiator cost to run?

Run the numbers on your own use

Change any of these and the figures update. The defaults are the typical case described above; your rate is the input that moves the answer most.

Why this is lower than the number you will see elsewhere

Almost every published answer to this question multiplies the rating on the label by the hours the appliance is switched on. For an oil-filled radiator that gives 1,800 kWh a year, or $330.

Slightly lower than a fan heater’s because the oil is a thermal store: it keeps radiating after the element cuts out, so the thermostat waits longer before calling again.

The arithmetic, step by step

Nothing here is hidden, so you can check it or change it. Working in the order the formula runs:

1. 1,500 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 45% — the share of its in-service time it is really pulling that. Slightly lower than a fan heater’s because the oil is a thermal store: it keeps radiating after the element cuts out, so the thermostat waits longer before calling again.
   That gives 675 W averaged across the hours it is on.
3. × 8 hours a day × 150 days — One room, heated through the evening across a northern winter.
   675 × 8 × 150 ÷ 1,000 = 810 kWh a year.
4. × 18.34¢ — the US average residential rate for June 2026.
   810 kWh × 18.34¢ = $149 a year.

Change any assumption in the calculator above and every figure on this page moves with it. The two that matter most are your rate, which varies 4× across the country, and the hours — the duty cycle is a property of the appliance, but the hours are a property of you.

How sensitive is that number?

A single figure invites more confidence than it deserves. Here is the same appliance under assumptions either side of the default, so you can see how much of the answer is the appliance and how much is the guess about how you use it.

Everything else held at the default. The spread here is the honest error bar on the headline figure.

What it costs per hour, day and month

At 18.34¢ per kWh, the US residential average for June 2026.

The thing worth knowing

The oil is a flywheel, not an efficiency gain. It stores heat and releases it gently, which makes the room temperature steadier and the heater quieter — but every joule in the oil arrived through a resistance element at exactly 100% efficiency, the same as any other electric heater. It cannot produce more heat per kilowatt-hour than a bare wire, and nothing sold can.

Against heat pump (heating)

A heat pump delivers two and a half to four times the heat per kilowatt-hour because it moves heat rather than making it. Failing that, heat the person: a heated blanket costs about a fiftieth of this. In numbers: an oil-filled radiator costs $149 a year on these assumptions, and heat pump (heating) doing a comparable job costs $423 — a difference of $274 a year, or $2,745 over ten years at today’s rate.

Both at 18.34¢/kWh, each on its own standard usage assumption. Ten years is roughly the service life of either.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this oil-filled radiator costs $427 a year in Hawaii and $106 in Nevada — a difference of 4×.

Cost of running one oil-filled radiator for a year, by state. Residential average price, EIA June 2026.

Other heating and cooling costs

• Electric furnace

  $1,653 a year

  Whole-home resistance heating in a cold climate.

• Heat pump (heating)

  $423 a year

  Whole-home heating in a mixed climate.

• Central air conditioner

  $421 a year

  A 3-ton system in a hot-summer climate.

• Dehumidifier

  $228 a year

  A 50-pint unit holding a basement at 50% relative humidity.

• Electric baseboard heater

  $218 a year

  One 1,000 W baseboard unit in one room. Most homes have several.

• Heated towel rail

  $193 a year

  Left permanently on, which is how most of them are used.

Questions

Source: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A, June 2026. U.S. Government work, public domain.

How every figure on this page is computed · Where the data comes from