garage heater power consumption (1)

If you are planning to buy a new electric garage heater or wondering how much electricity your existing electric garage heater is consuming then this article is for you. In this article, we will calculate the power consumption of an electric garage heater and also look at how much it costs to use one.

Also by the end, you will learn to calculate the power consumption of any electric garage heater using a simple calculator.

Electric garage heaters are normally rated between 3000 watts to 10,000 watts. A 5000 watt electric garage heater running for 8 hours in a day will consume around 20 kWh of electricity in a day. This adds up to around 600 kWh of electricity in a month.


Electric Garage Heater Power Consumption:

The power consumption of an electric garage heater (for that matter any electrical appliance) depends upon two main things,

  1. First is the wattage of your electric garage heater,
  2. And second is the electricity tariff in your area.

Before we jump into calculating the power consumption of your electric garage heater let’s see what these terms are and how you can find out your electric garage heater’s wattage and the electricity tariff of your locality.

If you already know these terms and just want to use the calculator then please scroll down to use the calculator.


What is the Wattage of an Electric Garage Heater:

5kW Electric Garage Heater

The wattage of an electric garage heater varies from 3000 watts to over 10,000 watts, the higher the wattage, the larger and quicker the room it can heat, and the higher the power consumption.

You can find the wattage of your electric garage heater by reading the label on it or just look for your electric garage heater on amazon and you will find its wattage in the description section.

(If you don’t have time to do this, then don’t worry I have put together a table at the end that shows the power consumption of a range of electric garage heaters with different wattages.)

If you don’t know what a watt is then here it is,

Watt is the unit of power. It means the rate at which electricity is consumed or produced by a device. For example, a 50-watt TV consumes power at a rate of 50 watts per hour, it does not mean that the TV consumed 50 units of electricity, it means it will consume power at a rate of 50 watts every hour.

So in short, the wattage of an electric garage heater lies between 3000 watts to 10,000 watts and you can find it by looking at the label on it. With that out of the way, let’s look at what is electricity tariff.


What is your Electricity Tariff:

In simple words, electricity tariff is the amount your electricity provider charges you for one unit (kWh) of electricity. I live in Mumbai, India here the electricity tariff is Rs 12/kWh.

(What is a Kilowatt hour (kWh) Kilowatt hours or units of electricity is the energy consumption of a device. For example, a 50-watt table fan running for 50 hours will consume 50 watts x 50 hours = 2500-watt hours = 2.5-kilowatt hours of electricity = 2.5 units of electricity. (1 kWh of electricity = 1 unit of electricity))

To find your electricity tariff, just look into your previous month’s electricity bill and find out your monthly electricity consumption, then just divide your monthly electricity consumption by your total monthly electricity bill, the figure you get is approximately your electricity tariff.


Calculate Electric Garage Heater Power Consumption:

With these two pieces of information in hand, you are ready to find the power consumption of your electric garage heater.

garage heater 10kw wattage
10kW Electric Garage Heater from Dyna-Glo

Let me show you an example,

I have selected a 10kW electric garage heater listed on home depot. Let’s assume we will be using it for 8 hours every day throughout the year.

Hence, we will calculate the power consumption of this 10kW watt electric garage heater in a day, in a month, and in an entire year.

Few things to know before we start with the calculation,

  • The electric garage heater we have selected has dual power mode, 7.5 kW and 10 kW, meaning you can run the heater either at 7.5kW or 10 kW, hence in both cases the power consumption will be much different.
  • Second thing is, an electric garage heater does not run continuously, once the set temperature is reached, the heating element (which consumes almost 90% of the power) stops and kicks back up when the room temperature falls a couple of degrees below.

Hence, in reality, when we run the electric garage heater for 8 hours, its heating element (which consumes most power) only runs half of the time, the rest of the time its heating element is off.

Hence for 8 hours of operation, we will only consider 4 hours of run time during our calculation. (50% of 8 hours is 4 hours)

Also, the power consumption largely depends on the proper selection of garage heater, if you are using a small garage heater for a large area, then the heating element will be running all the time as it will take a long time to heat the air inside the room, hence power consumption will be more.

And vice versa is also true, if you are using a large heater for a small garage, then the heating element will be on for very less time, as it will heat the room faster.

With the knowledge of your electric garage heater wattage and your electricity tariff, just use this simple formula to calculate power consumption.

Power consumption of a 10kW electric garage heater = Wattage of the garage heater X operational hours

Cost to run a 10kW electric garage heater = Power consumption of the garage heater X electricity tariff.

(Operational hours is basically the number of hours you are using your electric garage heater)

Now let’s calculate


Electricity consumption of A 10kW Electric Garage Heater:

In our case, wattage is 10kW and operational hours are 4 hours in a day, (half of 8 hours as the heating element only runs 50% of the time), 120 hours in a month, and 1,460 hours in a year.

Hence by using the above formula.

Power consumption of a 10kW electric garage heater in a day (8 hours) = 10 kW X 4 hours = 40 kWh

Similarly, Power consumption of a 10kW electric garage heater in a month (8 hours/day @ 30days) = 10 kW X 120 = 1,200 kWh

And Power consumption of 10kW electric garage heater in a year (8 hours/day @ 365 days) = 10 kW X 1460 = 14,600 kWh

Now that we know the power consumption just multiply it by your electricity tariff and you will get how much it will cost you to run your electric garage heater.

let’s calculate how much it will cost to run this 10 kW electric garage heater for an entire month in Los Angeles, London, and Mumbai.

  • In case of Los Angeles, the electricity tariff in Los Angeles is around 25.8 cents per kilowatt hour (kWh), hence it will cost around $ 309.6 (1200 kWh X 25.8 cents) to run this 10kW electric garage heater for 8 hours every day for an entire month.
  • In case of London, the electricity tariff in London is around 36p/kWh, hence it will cost around £ 432 (1200 kWh X 36p/kWh) to run this 10kW electric garage heater for 8 hours every day for an entire month.
  • In case of Mumbai, the electricity tariff in Mumbai is around Rs 10 per kilowatt hour (kWh), hence it will cost around Rs 12,000 (1200 kWh X Rs 10) to run this 10kW electric garage heater for 8 hours every day for an entire month.

For your reference, I have calculated the cost to run this 10 kW electric garage heater for 8 hours daily throughout the entire year in Los Angeles, London, and Mumbai. (For the calculation I have assumed 4 hours of operation as we now know the heating element is only ON for 50% of the time.)

Country (Tariff)Daily Power Consumption of an Electric Garage HeaterMonthly Power Consumption of an Electric Garage HeaterAnnual Power Consumption of an Electric Garage Heater
Los Angeles (25.8 c/kWh)40 kWh, $ 10.32120 kWh, $ 309.614,600 kWh, $ 3,766
London (36p/kWh)40 kWh, £ 14.40120 kWh, £ 43214,600 kWh, £ 5,256
Mumbai (Rs 10/kWh)40 kWh, Rs 400120 kWh, Rs 12,00014,600 kWh, Rs 1,46,000

The above figures show the approximate power consumption of a 10 kW electric garage heater, however, the actual power consumption will greatly depend on room insulation, proper sizing of the heater, model of heater used, and other factors.

Also, most of us use the garage heater only during winter which lasts for 2-3 months in most places.


Electricity consumption for different Wattage Electric Garage Heaters:

For your reference, I have made the below table which shows the power consumption of a range of electric garage heaters having different wattages. I have assumed 8 hours of operation every day for an entire month.

(Over here as well, for the calculation I have assumed 4 hours of operation as we now know the heating element is only ON for 50% of the time.)

Electric Garage
Heater Wattage
Daily Power ConsumptionMonthly Power ConsumptionAnnual Power Consumption
3000 watts12 kWh360 kWh4,380 kWh
5000 watts20 kWh600 kWh7,300 kWh
7500 watts30 kWh900 kWh10,950 kWh
10,000 watts40 kWh1200 kWh14,600 kWh

As I said before, these are approximate figures and definitely on the higher side if you are using a correct-size garage heater.

Now go ahead and use the below calculator to find out the power consumption of your electric garage heater.

Just type the wattage of your electric garage heater, hours of usage, and your electricity tariff, and let the calculator do the math for you. Don’t forget to divide your daily operational hours by 2.


Electric Garage Heater power consumption calculator:

If you are not happy with the approximate results and you want to know the exact power consumption, then I would suggest you buy a cheap Kill-A-Watt Meter from amazon.


Calculate the exact power consumption of any Appliance using Kill A Watt Meter:

Kill A Watt Meter is a simple device that gives real-time data on the power consumption of any device.

You can check it on amazon using this link – Kill A Watt Electricity Usage Monitor

To use a kill-a-watt meter to calculate the power consumption of your electric garage heater, first, connect your electric garage heater plug into the kill-a-watt meter and then plug the kill-a-watt meter in your wall socket and you are good to go.

Then start using your electric garage heater and you can see in real-time how many kWh (units) of electricity it is consuming.

Check out the following articles to know the power consumption of other appliances:

You can check out this article to know more about the power consumption of common household appliances.

Check out my articles on solar power for home and how it can help you save your electricity bill.

Thank you for reading.

Aavjo 👋


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