What does an electric underfloor heating 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 electric underfloor heating that gives 1,920 kWh a year, or $352.

Thermostatic, and the floor’s mass means long slow cycles rather than short sharp ones. The wattage is roughly 12 W per square foot of heated area.

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. 1,200 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 35% — the share of its in-service time it is really pulling that. Thermostatic, and the floor’s mass means long slow cycles rather than short sharp ones. The wattage is roughly 12 W per square foot of heated area.
   That gives 420 W averaged across the hours it is on.
3. × 10 hours a day × 160 days — About 100 square feet of bathroom floor, on a timer through the heating season.
   420 × 10 × 160 ÷ 1,000 = 672 kWh a year.
4. + standby — 2 W for the other 14.0 hours a day, which is 4.5 kWh a year. People leave this out and it is not always small.
5. × 18.34¢ — the US average residential rate for June 2026.
   676 kWh × 18.34¢ = $124 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

Electric underfloor heating is resistance heat, so it is the most expensive way to produce warmth per kilowatt-hour. What justifies it is that a warm floor makes a room feel comfortable at a lower air temperature, and that it is often heating one small room instead of a whole house. Used as a whole-home heating system it is ruinous; used for a bathroom floor for two hours a morning it is a modest and pleasant expense.

Against heat pump (heating)

A programmable thermostat that brings the floor up before you get out of bed and lets it go afterwards. Running it continuously multiplies the cost by four or five for no benefit at three in the afternoon. In numbers: an electric underfloor heating costs $124 a year on these assumptions, and heat pump (heating) doing a comparable job costs $423 — a difference of $299 a year, or $2,990 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 electric underfloor heating costs $357 a year in Hawaii and $89 in Nevada — a difference of 4×.

Cost of running one electric underfloor heating 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