How Much Electricity Does a Space Heater Use?

Written by: Paul Cathro

Updated on: February 16, 2022

Calculate how much your space heater is costing with our simple formula. Budget for your heating bills in no time!

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When the winter chill bites or your central heating system fails, most of us turn to an electric space heater to keep us toasty.

An electric space heater is a great invention because they are portable and allows us to aim them into the spaces that we want warming the most.

Yet, one of the biggest questions is how much does it cost to run a space heater?

To understand the cost of using a space heater, we first need to know how much energy does a space heater use.

Read on below to find the all-important formula to work this out, and many other considerations when thinking about your electricity bill and using an electric space heater.

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Recommended Next: Don’t miss our guide to the top efficient space heaters.

How to Calculate Space Heater Usage & Cost

It is possible to calculate how much electricity a space heater will use – and the cost of using one.

It won’t take a mathematics degree to find the magic number, but it will require you to do a little bit of research on the space heater that you own (or are considering buying) first.

#Step One: Wattage and Kilowatts

The first of two steps is to uncover the wattage of the space heater. The wattage is a measurement of how much electricity is required to make the product function.

This is usually easy to spot and is printed on the space heater packaging, the product itself or in the manual.

If you have owned your space heater for some time and have thrown away packaging or manuals, you can usually still find the wattage with a quick search online.

The majority of electric space heaters have a wattage of 1,500. This is standard with a few models using slightly more or slightly less electricity.

This means most electric space heaters use 1.5 kilowatts because 1,000 watts is equal to one kilowatt.

Related: We explain how to prevent a space heater from blowing a fuse.

#Step Two: The Magic Formula

Electricity bills are calculated using kilowatt-hours, which translate to how much energy is required to make a one-kilowatt appliance run for one hour.

Thus, we can use a formula to take the wattage of an appliance and work out electricity usage and cost for a specific amount of time.

In the example below, the wattage of the space heater is multiplied by the number of hours it is switched on for (in this example: five).

1,500 (watts) x 5 (hours) = 7,500

The next step of the calculation is to divide the total by 1,000

7,500 / 1,000 = 7.5

The final step of the calculation is to multiply the previous result by the amount of your electricity supplier charges.

This will be different for different people, but for the sake of argument and the example, let’s imagine the supplier charges $0,30.


$0.30 x 7.5 = $2.25

It will cost $2.25 to use the electric heater for five hours.

To work out how much it costs per hour, simply divide this number by five ($2.25 / 5 = $0.45).

turn heating down

Related: What safety features should a reliable space heater have? 

Other Factors Affecting Cost

The above calculation is going to be applicable for most households, but there is one main exception.

If you are a homeowner with solar energy, the calculation above may not be applicable because you will be using the electricity you accumulate.

If you sell electricity back to your supplier, you could even be making money while running an electric space heater.

Another factor that may influence the cost of running an electric space heater is the condition of the appliance.

If the appliance is damaged, there is a chance that it will use more electricity, which is more importantly dangerous and can affect the overall cost of using the space heater.

woman beside space heater

Top Tips for Using an Electric Heater Effectively

There are a number of things that homeowners can do to maximize the effectiveness of their space heater and cut down the bills at the same time.

Here are some additional points to consider:

  • Use the right size space heater for the space you intend to heat. Different heaters are available that have been specifically designed for desks, bedroom and larger spaces.
  • Keep it on low if you have the option. Most modern space heaters include settings. Use this to your advantage by keeping the heating on lower for longer rather than turning it on and off repeatedly only using its maximum setting.
  • Remember to unplug your space heater if you are leaving the room for a while. This is not only important to keep the electricity bill down, but also for the safety of your home and family.
  • Never place clothes to dry on or in close proximity to the space heater.
  • Do not use the heater right up until the time you go to bed. Remember, the heater will have warmed the room previously and the room will remain warm for some time after it has been switched off.

Recommended Next: Check out our buying guide to finding the safest infrared heaters on the market today.

Are Electric Heaters  a Worthwhile and Cost-Effective Heating Strategy?

The results are in – but does that make an electric space heater a cost-effective and worthwhile heating strategy? The answer is that it depends.

If you have the option of a central heating system, then it is highly likely that this system will be cheaper to operate in comparison.

However, if you are experiencing a cold winter or your central heating is undergoing maintenance, an electric space heater can be a cost-effective solution given the situation.

The overall space heater electricity consumption is not significantly high, but if you choose to use it every day then the costs can soon add up. It may be that you opt for an electric space heater on severely cold days or limit its usage throughout the year.

Running an electric heater continually or instead of a central heating system is not a wise choice if you want to save some hard-earned dollars.

About the Author Paul Cathro

Paul is an ex-HVAC engineer with 5 years 'in the trade'.

He acquired in 2022 and aims to make it the internet's most comprehensive HVAC resource for small homes in the next few years.

You can learn more about Paul's story here.

Browse his published work on the website here.

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