An electric space heater uses approximately 1500 watts; on average, an electric space heater is used for around 5 hours a day.

Enter the number of usage hours and power setting (in wattage) of electric space, and click the calculate button to know power consumption and running cost per hour, day, week, and year.

*Based on $0.12/kWh electricity cost and 5 hours daily usage. Actual energy consumption and cost may vary. For information and to compare models, visit

Electricity Usage Of A Space Heater

The electricity usage of a space heater depends on its power rating and the duration of use.

A higher power rating means that the heater consumes more electricity, while longer durations of use also result in higher electricity usage. It is important to note that using a space heater continuously can result in high electricity bills.


For example, a 1,500-watt space heater used for 8 hours per day would consume 12,000-watt hours (or 12 kilowatt-hours) of electricity per day. This translates to approximately $1.44 per day, assuming an electricity rate of $0.12 per kilowatt-hour.

What Is The Average Power Of An Electric Space Heater?

Electric space heaters are designed to convert electrical energy into heat through resistive heating elements.

To calculate the electricity usage of a space heater, one needs to know its wattage rating and the number of hours it will be used.

The power rating of a space heater indicates the amount of electrical energy it consumes and the amount of heat it can produce. A higher power rating means that the heater can produce more heat, but it also consumes more electricity.

What Is A Space Heater Power Rating?

Now that you have figured out how much power your space heater uses in terms of wattage (W), the next step would be to determine your heater power rating so that you can have a rough estimate of your heating bill.

A space heater power rating refers to the amount of electrical power that a space heater consumes and the amount of heat that it can produce.

The power rating is typically measured in watts and can range from as low as 200 watts to as high as 5000 watts or more, depending on the size and type of the heater.

In general, a space heater that utilizes either 120V or 240V to run will more or less consume the same amount of energy and therefore generate heating bills that are not too disparate from each other.

If you have gas central heating then this will be a lot cheaper to run than an electric heater considering the power consumption.

Heating bills also directly translate into electricity bills. Each electricity bill is measured in kilowatt-hours (kWh).

In other words, the electricity bill is determined by the amount of energy used by a 1-kilowatt heating device for an hour.

In order to ascertain how much a 1.8 kW space heater will cost you, you may use this simple equation:

No. of Watts used by your space heater x No. of hours the heater is used

For example, if you wish to watch your favourite sports program on television for two hours in a row, and you leave your space heater turned on to retain the warmth in your living room:

1,800 Watts x 2 hours = 3,600

Next, divide the number you have attained by 1000:

= 3.6

Use the resultant number and multiply it by the utility charges for electricity designated to your region.

Since these charges vary from location to location, do take note that using the same space heater in different areas may grant you different overall charges.

So, if the local utility charges for electricity costs $0.75, for example, then:

3.6 x $0.75 = $2.70

This means that the heating bills for those two hours of luxurious warmth in your living room have just cost you a whopping total of $27.90.

If you use the same space heater for the same amount of time for the whole month, your monthly electricity bill from your space heater alone will shoot up to:

$2.70 x 30 days = $81.00

Remember, this is without factoring in the cost of taxes or any other additional fees!

The longer you turn on your space heater, the higher that little spike in your electricity bill will be.

This is why the United States Department of Energy has ascertained that bills stemming from heating devices amount to as much as 40% of overall household energy consumption in North American homes.

What Is The Electricity Consumption Of My Space Heater?

The power consumption of your space heater is different compared to its power rating.

Unlike the heater wattage rating, which is measured in kilowatts (kW), the power consumption is measured mostly in BTUs (although this can be measured in Watts (W) and Amperages (A) too).

A BTU is known as a British Thermal Unit.

It is instrumental in determining the energy output of a space heater since some heaters have multiple or different power levels, as well as unique heat settings.

BTUs are capable of ascertaining the heating capacity of not only electric-based space heaters such as ceramic heaters. Still, they can also calculate the thermal energy output of heaters that use fuel such as kerosene, paraffin, or gas heaters.

Additionally, it can also determine the capacity of cooling systems.

In most cases, the BTU of a space heater will be listed on the label on the heater itself.

But if it is nowhere to be found, you may manually calculate the BTU of your space heater using this basic formula:

Heater Wattage Rating (W) x 3.413 = BTU Output

3.413 is the amount of BTU that is equal to 1 watt of energy and, therefore, a standard in this circumstance.

Thus, a heater with a 1,800 Wheater wattage rating would be 1,800 W x 3.413 = 6143 BTU.

This means that a 1,800 W space heater is capable of delivering 6143 BTU of heat, and a larger space heater of 5,000 W will provide at least 17,065 BTU of heat.

Thus, a heater with a higher BTU rating would generally have greater power consumption.

Will A Larger Space Heater Consume More Electricity?

Technically, yes. Many factors contribute to the power consumption of a space heater, from energy efficiency to shape, weight, and design.

But the most notable factor is the size of the space heater itself.

Throughout the next few lines, we shall explore the power consumption of a space heater according to its size and its relevant heating capacity:

  • 2557 BTU Heaters

A space heater with 2557 BTUs is sufficient enough to heat a 100 square feet room or office space. The wattage required to run a heater of this size is approximately 750 W.

  • 6820 BTU Heaters

Space heaters with 6820 BTUs require at least 2000 W to run. They are also capable of heating an enclosed space of up to 250 square feet.

  • 13640 BTU Heaters

An even larger space heater of 13640 BTUs needs approximately 4000 W to operate.

A heater of this size can provide warmth in a larger room or space, such as a parking garage or hall of up to 450 square feet.

Therefore, the larger the heater, the higher the amount of power required to operate the heater concern.

With more Watts consumed, more warmth is provided per square foot, and more heating units are allocated for each electrical group that is being consumed.

In other words, the heater wattage is significantly increased.

Likewise, the size of the space heater increases as well since a larger device would be needed to generate a more significant amount of thermal energy to radiate additional warmth at a larger radius.

With the increase in power consumption, naturally, you will observe a staggering rise in your electricity bill.

Although heating costs vary from region to region, as discussed earlier, the acceptable standard electricity rate in the US hovers around an average of $0.12 kW per hour.

Infrared heat is safer than conventional, resistive heat, but it takes just as much electricity to produce it.

If a heater with a 9000 BTU, for example, were run continuously for six hours a day, it would generate an overall cost of $0.52 daily. The monthly bill will then chalk up to $15.60.

Although this might not seem too much at first, once you take into account the additional cost of running a fan heater, you will need to multiply that value by three.

This will then elevate the total heating cost to $46.80.

Do Different Brands Of Heaters Consume Power Differently?

Simply put, yes. Each brand of heater has been exclusively designed to have an output of different units of heat per unit of power consumed.

  • Depending on the type of heater being used (fan heaters, heat pumps, or even radiators), the amount of space that can be warmed up varies as well, also if the same number of BTUs is being used.
  • Therefore, you must select your heater according to the size of the space you need to keep warm and your financial capacity.
  • Make sure you take your time to evaluate and study each heater at the store thoroughly and do take note of all their built-in safety features.
  • In most cases, the specifications of each heater, including the Wattage (W), Voltage (V), and Amperage (A), as well as BTUs, will be listed.

It is, therefore, your responsibility to select the most appropriate heater that will benefit your home or office in the best of ways.

What Are The Most Efficient Heaters That Consume Less Power?

There are three main types of heaters that have been noted to consume power at an efficient rate:

  • Fan Heaters

This type of space heater provides less than 1 unit of heat per unit of power consumed. This is because the fan within the radiator itself consumes additional power.

  • Heat Pumps

Space heaters that utilize heat pumps are highly efficient, with a consumption of up to 3 units or more of heat per unit of power consumed.

Heat pump-based heaters are, therefore, much more significant and usually far less portable. Still, due to their strength and heating capacity, they can put out enough thermal energy to warm up a more substantial, enclosed space.

  • Radiators

Radiator-based space heaters are usually highly portable. They exude 1 unit of heat for each group of power consumed but are highly old-fashioned and can be hot to the touch.

Despite this, they do remain highly prevalent in some countries, such as the UK and Russia.


Thus, the power consumption of space heaters is mainly dependent on several key factors, such as the size and heating capacity of each heater, as mentioned above.

However, different types of heaters also contribute to the efficiency, power consumption, and heat output of each space heater.

Therefore, the next time you flick out that credit card to go space heater shopping, it is best that you read through the specifications of each brand and type of heater first and draw your comparisons and conclusions.

Ultimately, it is up to you to decide which space heater to bring home and keep those fingers and toes warm and comfy throughout the day.