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As a rule, all oil-filled space heaters carry a maximum power rating of 1500 Watts (W), which is the staple norm for most portable heating devices.

However, some brands of space heaters may carry models which have a threshold energy rating of either 700W to 800W. Use below calculator to find average power consumption of an oil-filled space heater of 750 Watts for 6 hours a day @ $0.12 per kWh. Also know running cost of heater per hour, day, week and for a year.

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How Much Power Does Your Oil-Filled Space Heater Consume?

Now that you have the basic rundown of how your oil-filled space heater operates, you must determine the amount of power consumed by the heating device in your home.

Sometimes, there might be a tertiary setting that lies between these two designated figures.

Oil filled space heaters provide the flexibility that allow you to overcome this difficulty. They're designed to be moved from room to room and draw a relatively small amount of power, compared to the average furnace (400-1500 watts on average), so you can add heat strategically in order to optimize your environment .

Therefore, if you are on the hunt for an oil-filled space heater to be added to your living quarters, you should take note of both the minimum and maximum power range your heater is capable of consuming.

The amount of power used by your oil-filled space heater is crucial in the determination of exactly how much money you will need to fork out over your heating bills much later.

You must also remember to factor in the additional cost of taxes as well as any extra fees that might be piled on top of your regular heating bill, which can vary from location to location on a global scale.

How Can You Determine the Amount of Energy Used by Your Oil-Filled Space Heater?

Before you head off and whip out your calculator to ascertain your future heating bill caused by your oil-filled space heater, you must first have a tight grasp on the universal principle of heater wattage.

Each electrical device that you own under your roof features two different wattage ratings by default.

The first rating caters to the power consumed by the device itself, while the second rating is related to the heating capacity of your unit.

This concept applies to your oil-filled space heater as well since it uses electricity to operate optimally.

The two wattage ratings can usually be located in the owner’s guidance manual or mini booklet that is given to you during the moment of purchase of your space heater or can be printed on either the back or the side of your device.

Either way, the rating is given usually confers to the power output and not the amount of power which is directly consumed by your oil-filled space heater.

For you to unearth the exact amount of power utilized by the space heater you have now procured; you will need to steal a glance at the label stamped at the back or the bottom of your device.

Under normal circumstances, the electrical ratings will be printed very clearly on the label itself. These figures will be denoted in either Amperage (A), Voltage (V) or Watts (W).

Now that you have finally attained some substantial numbers to crunch, you can ascertain the heater wattage of your device by following the formula listed below:

Watts (W) = Volts (V) x Amps (A) x Power Factor.

Universally speaking, the Power Factor has been coined at an accepted standard of 1 unit.

However, there is a collection of electrical devices that do not fall within this rule.

Now that you have figured out the exact amount of Watts consumed by your oil-filled space heater, your next step would be to determine its overall efficiency.

You may use the formula depicted below to do so:

x 100 =  %

The power input of your oil-filled space heater can be derived from the percentage (%) calculated from the formula above.

For example, a space heater usually runs on 120V to 240V, based on the model you have acquired and the manufacturing location of the device.

For this purpose, we will simply use an oil-filled space heater with a label of 120V and 12.5A. According to the equations listed above, this means your space heater has a power consumption of:

120V x 12.5A x 1 = 1500 Watts

You can further derive this value into kilowatts by merely dividing the amount of Watts by 1000:

Therefore, your oil-filled space heater consumes:

How Much Does Your Oil-Filled Space Heater Cost to Operate?

Now that you have deduced the exact amount of power consumed by the oil-filled space heater in your house, you will need to ascertain the heater power rating next.

This will give you a rough idea of how much your heating bill will chalk up to when you set your space heater to work and allow you to plan your finances accordingly.

As mentioned earlier, most oil-filled space heaters will run on either 120V or 240V and require almost similar energy levels to operate without a hitch.

This means your heating bills should not diverge too much from one another, should you either select a device that uses 120V or 240V to operate.

By heating bills, this directly confers to your electricity bills. No one likes to see a humongous spike in their electricity bills, especially during winter, when the cost of enveloping yourself in heavenly warmth often reaps a steep price.

But by figuring out how costly a 1.5kW oil-filled space heater might be, you can use the formula listed below:

No. of Watts used by the oil-filled space heater x No. of hours the heater has been operating

A quick example: You are now in your living room, and you want to watch your favourite movie on television in complete comfort.

But the room is chilly to the bone, and those two layers of sweaters are not doing much to buffet against the icy claws of the cold.

Instead of rubbing your hands up and down your arms repeatedly in a futile effort to stay warm, you decide to crank up the heat by turning on your oil-filled space heater for the next three hours. Sounds familiar?

Well, here is what those three hours of blessed heat is going to cost you:

1500W x 3 hours = 4500

Divide the number you have derived above by 1000 next:

= 4.5

Quickly look up the electrical utility charges that have been designated to your local area or region, as determined by your local electrical department.

Do take note that these charges will vary in different locations, and each country has a different set of laws and subsequent tax inclusions added to your electricity bill.

Therefore, using the same space heating device in a different region or area might cost you less or more, depending on the designated charges.

Now, use that number you have just attained and multiply it against the electrical utility charges established by law in your area.

The average nationwide electrical charges will cost approximately $0.17 in the United States.

By taking note of this assumption into account, your charges should be approximate:

4.5 x $0.17 = $0.765

This translates to a total of $0.765 in heating bills for those three hours of much-coveted warmth that you craved so desperately to enjoy to watch your weekend entertainment.

If you decide to utilize the same oil-filled space heater for three hours every day for a month in your home, then the total of your monthly heating bill would add up to roughly:

$0.765 x 30 days = $22.95

Do not forget! This is without including any additional hidden costs that your heating bills might be subject to, such as extra fees or taxes.

Thus, the longer you keep your oil-filled space heater turned on, the higher your electricity bill will be in the long run.

What Is an Oil-Filled Space Heater?

All oil-filled space heaters are typically old-fashioned in terms of usage and design. Although the advancement of technology has given rise to the creation of newer models with the harrowing promising of increasing overall energy efficiency by the triple fold, the principle behind the heater use remains untouched by the ravages of time.

Valued for their efficiency and portability, space heaters present one of the most budget-friendly options for heating your home, garage or even office cubicle at any given the time of day.

An oil-filled space heater generally carries the outward physical appearance of a radiator with a series of connected panels attached in uniformly shaped folds.

These folds are also labelled as ‘fins’, and diathermic oil flows through them in a closed-loop.

Since the oil is trapped within the fins with no possibility of escaping whatsoever, the space heater does not require to be refuelled or the oil in it to be replaced.

The oil itself does not burn off or evaporate, no matter how long the space heater has been put to use.

A thermostat is often attached to each oil-filled space heating unit to monitor any fluctuations in temperature of the internal heating system that operates within the boundaries of the metal fins.

When the oil within the space heater is heated to its optimal temperature, the sensors pick up on this surge in heat and relay a signal to the thermostat, which then switches off the power feeding the space heater.

Under ideal circumstances, the space heater should kick back into gear as soon as the thermostat detects a plummet in the oil’s temperature.

How Does an Oil-Filled Space Heater Work?

With a myriad of designs, shapes, and models propped on the shelves of various stores worldwide, you can select any space heater that meets your needs or requirements with the quick swipe of your credit card or flip of the stack of green notes nestled neatly in the confines of your wallet.

But with significant divergence in variability, you might also have trouble picking out which type of space heater that benefits yourself and your loved ones the most this upcoming winter season.

What you need to take note of is that all space heaters usually fall into two major categories: convective and radiant.

While convective-based space heaters use the convection of hot air particles via the aid of motor pumps or fans to radiate heat to a nearby person or even specific object, radiant-based heaters usually consist of a diathermic oil that is circulated through interconnected panels to emit heat to its surroundings.

Thus, this type of space heaters is more commonly dubbed as ‘oil-filled’ space heaters.

When an electrical current is transmitted through your oil-filled space heater, the current will surge through the resistor nestled protectively within the interior of the device, which in turn transforms the resultant energy into heat.

Any amount of heat that is produced is then absorbed by the oil circulating within the fins of the space heater.

As the oil continues to circulate in a never-ending loop-like fashion, it transfers the heat it has retained into the metal barriers of the fins, which then causes the space heater to heat up and have a high surface temperature.

As the diathermic oil continually moves through the fins, this will also radiate warmth to its surrounding environment, including any objects or individuals that are located nearby.

This method of heating grants all oil-filled space heaters at least 99% energy efficiency.

Unlike other space heaters such as gas heaters which require the combustion of propane gas to generate heat, nearly all the electricity that transfuses through an oil-filled space heater is converted directly into heat with minimal energy loss along the way.


In a nutshell, by following the equations and steps outlined above, you can quickly determine the amount of electricity consumed by your oil-filled space heater.

Bearing in mind that this figure alters from region to region and might carry extra charges, your electricity bill is also highly dependent on the amount of time you keep your space heater turned on.

Other factors that can contribute to the overall electrical cost include what time of the day you use your space as well as what time of the year your space heater is being used.

With that in mind, it is always highly encouraged that you reduce the usage of your oil-filled space heater to stave off the possibility of incurring a significant peak in your next electricity bill.

It does pay to be cautious and set aside the necessary amount of finances for your heating bills.

After all, you wouldn’t want to spend Christmas in the blistering cold of your living room now, would you?