How much does it cost to run my heater?

That’s a loaded question with many variables. What is the outside temperature? How warm do you want it to be inside your room? How large is the room? How well insulated are the walls? What kind of furniture is in the room? What is your local electric rate? Need I go on?

What we can tell you is what is the absolute worst-case scenario: How much it would cost if the heater was running constantly for an hour. (If you have the right size heater for your room, it would be very rare for it to be running for an hour straight. Your heater will be hooked up to a thermostat, which will only turn the heater on when it needs heat in the room.)

But before we do the calculations, you need to figure two things out:

  • the wattage of your heater/the total wattage of the heaters you are using
  • your local electrical rate

The basic equation to determine the cost of running a heater is:

kW x electric rate = total cost/hour

Your electrical rate will be based on kilowatt-hours (kW). Here in Vancouver, Washington our local electric provider charges  about 8 cents per kW for residential customers.

Let’s say that we’re using two 750-watt heaters to heat a large room in our home, for a total of 1,500-watts.

First thing we need to do is convert the watts into kilowatt-hours by dividing by 1,000. The answer is 1.5, which means the two heaters will use 1.5 kW of electricity each hour they are in use.

Next we’ll multiply 1.5 kW by the electric rate (8 cents) to get the total cost of running the heaters for an hour straight. In this case, it would cost us $0.12 per hour to use the two heaters or $2.92 to run them constantly for 24 hours.

Now don’t forget, this is an extremely simplified way to estimate your cost of running the heaters. (Remember all those variables at the top of this post?)

In some states electric rates can vary based on the time of day or can increase once you reach a certain kW threshold per month.

It’s also safe to assume that your heater will not be running constantly most of the time. Your thermostat will check the room temperature a few times per hour — how often, depends on your individual thermostat. If the thermostat senses that the room has reached the set temperature, it will tell the heaters to turn off. They will remain off until the thermostat determines the room temperature fell below the set temperature.

So if it’s 20° F outside and you want it to be 70° F inside, your heater may run for the hour straight. If it’s 45° F outside and you want it to be 55° F inside, it may only run for 20 minutes an hour. It just depends.