How Much Does It Cost to Run an Infrared Heater?
You are standing in your basement office at 6 a.m., toes cold, and you are wondering what a wall-mounted infrared panel would add to your electric bill. That is a fair question, and the answer is simpler than most heating guides make it.
The cost comes down to one formula you can redo with your own numbers. Watts, hours, your local rate, and how often the thermostat lets the panel run. I will walk through the arithmetic, show you tables at three common US electricity rates, and then compare a panel's running cost against the space heater or baseboard you already know.
Key takeaways
- The formula is: watts divided by 1,000, times hours per day, times your rate in cents per kWh, times the thermostat on-time percentage, divided by 100. That gives you dollars per day.
- A 400 W panel running 8 hours a day at 60 percent on-time costs about 29 cents a day at 15 cents per kWh, or roughly 9 dollars a month.
- Infrared panels are resistance heaters, so they convert electricity to heat at 100 percent efficiency. A mini split with a coefficient of performance of 3 delivers three times the heat per dollar of electricity.
- The real savings come from heating one room instead of the whole house, not from the panel itself being cheaper per watt than a space heater.
The formula in plain words
Here is the whole calculation in one sentence. Take the panel's wattage, divide by 1,000 to get kilowatts. Multiply by the number of hours the panel is on. Multiply by your electricity rate in cents per kilowatt-hour. Multiply by the percentage of time the thermostat actually lets the panel run. Divide by 100 to turn cents into dollars.
Let me put numbers on it. Say you have a 400 W panel in a 12 by 12 foot basement office. You run it 8 hours a day. Your utility charges 15 cents per kilowatt-hour. The thermostat cycles the panel on about 60 percent of those 8 hours because the room holds heat between cycles.
400 divided by 1,000 equals 0.4 kilowatts. Multiply by 8 hours and you get 3.2 kilowatt-hours of potential energy. Multiply by 15 cents and you get 48 cents if the panel ran the full 8 hours. Multiply by 0.60 for the thermostat on-time and you get 28.8 cents per day. Multiply by 30 days and you get about 8.64 dollars per month.
That is the whole math. No hidden fees, no efficiency multipliers, no mystery. A resistance heater, which is what an infrared panel is, turns every watt of electricity into one watt of heat. The only variables are how many watts, how many hours, what your rate is, and how often the thermostat lets it run.
Infrared heater running cost calculator
Enter your panel's wattage, your daily hours, your local rate and your estimated thermostat on-time to get the daily cost in dollars.
Cost per day dollars
Hourly cost at different wattages
If you want a quick sense of what one hour of full-power running costs, here is a table at three rates. These assume the panel runs at full wattage for one hour with no thermostat cycling, so they show the maximum hourly cost.
| Panel wattage | kWh per hour | At 12 cents/kWh | At 18 cents/kWh | At 30 cents/kWh |
|---|---|---|---|---|
| 300 W | 0.30 | $0.036 | $0.054 | $0.09 |
| 400 W | 0.40 | $0.048 | $0.072 | $0.12 |
| 600 W | 0.60 | $0.072 | $0.108 | $0.18 |
| 800 W | 0.80 | $0.096 | $0.144 | $0.24 |
| 1,000 W | 1.00 | $0.12 | $0.18 | $0.30 |
Monthly cost at different wattages
Now the number you actually care about: what shows up on your bill. These assume 8 hours per day, 60 percent thermostat on-time, and 30 days in the month. Your real on-time will vary with insulation, ceiling height and how cold the room gets between cycles. A well-insulated room with a 9-foot ceiling might cycle at 40 percent. A drafty attic room might run at 80 percent.
| Panel wattage | kWh per month | At 12 cents/kWh | At 18 cents/kWh | At 30 cents/kWh |
|---|---|---|---|---|
| 300 W | 43.2 | $5.18 | $7.78 | $12.96 |
| 400 W | 57.6 | $6.91 | $10.37 | $17.28 |
| 600 W | 86.4 | $10.37 | $15.55 | $25.92 |
| 800 W | 115.2 | $13.82 | $20.74 | $34.56 |
| 1,000 W | 144.0 | $17.28 | $25.92 | $43.20 |
Why thermostat on-time matters more than you think
The thermostat on-time is the variable most people get wrong. A panel does not run at full power for every hour you have it switched on. Once the room reaches your set temperature, the thermostat cuts power. The panel cools down, the room loses a little heat, and the thermostat switches it back on.
In a well-insulated 12 by 12 room with a 9-foot ceiling, a 400 W panel might reach set temperature in 20 minutes and then cycle on for 10 minutes out of every 30. That is roughly 33 percent on-time. In a sunroom with single-pane glass and a vaulted ceiling, the same panel might run at 80 percent or more because heat escapes faster than the panel can replace it.
The practical takeaway: if your room is leaky or has high ceilings, the panel will run longer and cost more. If it is well-insulated, the panel will cycle less and cost less. You can estimate your own on-time by watching the panel for an hour once it is installed. Count how many minutes the surface stays hot. That fraction is your on-time.
Real-world examples by room
Let me walk through three common setups so you can see how the numbers land in practice.
A basement home office, 12 by 12 feet, 8-foot ceiling, carpeted floor, one exterior wall. A 400 W panel on a 120 V plug-in circuit. The room is reasonably insulated because it is below grade. On-time runs about 50 percent. At 15 cents per kWh, that is 0.4 times 8 times 0.15 times 0.50, which equals 24 cents a day or about 7 dollars a month.
A tiled bathroom, 8 by 6 feet, 8-foot ceiling, no insulation in the exterior wall. A 300 W panel on a 120 V circuit with a GFCI outlet. You run it 2 hours in the morning and 1 hour in the evening, so 3 hours total. On-time is high, maybe 75 percent, because tile floors and walls pull heat fast. At 15 cents per kWh: 0.3 times 3 times 0.15 times 0.75 equals 10 cents a day, or about 3 dollars a month.
A garage workshop, 20 by 20 feet, 10-foot ceiling, uninsulated walls, one overhead door. A 1,000 W panel hardwired to a 240 V circuit. You run it 4 hours on weekends. On-time is high, maybe 85 percent, because the space is large and poorly insulated. At 15 cents per kWh: 1.0 times 4 times 0.15 times 0.85 equals 51 cents per session, or about 4 dollars a month if you use it four weekends a month.
How a panel compares to other heaters on running cost
An infrared panel is a resistance heater. So is a 1,500 W space heater. So is an electric baseboard. So is an oil-filled radiator. They all convert electricity to heat at essentially 100 percent efficiency. A 400 W panel and a 400 W space heater cost the same to run for the same number of hours. The difference is not efficiency. The difference is how the heat reaches you.
A panel warms your skin and the surfaces in front of it directly, like sun on your face on a cold, still day. A space heater warms the air around it, and that warm air rises to the ceiling where you are not standing. In practice, a panel can feel comfortable at a lower air temperature than a space heater, which means your thermostat can sit a few degrees lower and you use less energy overall. But that is a comfort effect, not an efficiency effect.
A ductless mini split is different. It moves heat from outside air into your room using a compressor. A mini split with a coefficient of performance of 3 delivers three units of heat for every unit of electricity. That means it costs roughly one-third as much to run as a resistance heater for the same heat output. In mild climates, a mini split is almost always cheaper to run than any resistance heater, including an infrared panel.
| Heating type | Effective heat output | Monthly cost | Notes |
|---|---|---|---|
| Infrared panel, 400 W | 400 W | $8.64 | Direct radiant warmth, no fan, no floor space |
| Space heater, 400 W | 400 W | $8.64 | Same cost, but warms air not surfaces, takes floor space |
| Electric baseboard, 400 W | 400 W | $8.64 | Same cost, slow to respond, can stir dust |
| Mini split, COP 3 | 1,200 W equivalent | $2.88 | Cheapest to run, but costs $2,000 to $4,000 installed |
When a panel is the wrong choice
I want to be straight with you about when the math does not favor a panel.
If you need to heat an entire house, a mini split or a heat pump will cost far less to run. A resistance heater, panel or otherwise, is the most expensive way to heat a large space. Panels make sense for one or two rooms, not for whole-house heating.
If you only need warmth for 30 minutes a day in a small space, a 1,500 W space heater that you plug in and point at your feet is simpler and costs about the same. A panel's advantage is that it runs quietly for hours without a fan, takes no floor space, and does not blow dust around. If you do not need those things, a space heater is fine.
If your room is uninsulated, has vaulted ceilings, or is full of single-pane glass, a panel will struggle to keep up. The on-time will climb toward 100 percent, the cost will climb with it, and you may still feel cold. In that case, fixing insulation or adding a window film will do more for your comfort and your bill than any heater.
Common questions about infrared heater running cost
Are infrared panels cheaper to run than a space heater?
For the same wattage and the same number of hours, no. Both are resistance heaters and cost the same per kilowatt-hour. The difference is that a panel's radiant heat can let you set your thermostat a few degrees lower because you feel warm at a lower air temperature. That comfort effect can reduce total energy use, but the panel itself is not more efficient.
How much does a 400 W infrared panel cost per month?
At 15 cents per kWh, running 8 hours a day with 60 percent thermostat on-time, about 8 to 9 dollars per month. At 30 cents per kWh, about 17 dollars. The exact number depends on your room's insulation and how often the thermostat cycles the panel on.
Does a panel cost more to run than an oil-filled radiator?
No. Both are resistance heaters. A 400 W panel and a 400 W oil-filled radiator draw the same watts and cost the same per hour. The panel heats surfaces directly; the radiator heats the air around it. Running cost is identical for the same wattage and hours.
Can I reduce the running cost of my infrared panel?
Yes, in three ways. First, improve the room's insulation so the thermostat cycles less. Second, use a timer or smart plug so the panel only runs when you are in the room. Third, if your utility offers time-of-use rates, run the panel during off-peak hours when the rate is lower.
Is a mini split always cheaper than an infrared panel?
For the same heat output, yes, because a mini split moves heat rather than creating it. A mini split with a coefficient of performance of 3 costs about one-third as much per hour to run. But a mini split costs $2,000 to $4,000 to install, while a plug-in panel costs $100 to $300. For one small room used a few hours a day, the panel's lower upfront cost can make it the better financial choice over several years.
