Tabby cat stretching near electric heater at home

Space heaters are fantastic appliances that can warm up your home, office, business or any other space so you can be comfortable even when it is freezing cold outside and using them as supplemental heating in your home can even lower your monthly expenses for some people. But before you commit, you should know how they work to make sure this heating alternative is right for you. Find out how many amps does a space heater use here to find out if they’re right for you.

Adding the perfect space heater to your home can make it a much more enjoyable place to reside, especially in the winter months.

Some heat systems simply aren’t the best, and replacing an entire HVAC system is expensive. So a small, portable space heater is the perfect solution to a cold indoor environment. But what does this mean for your electric bill or your power strips?

To understand how many amps a space heater uses, keep reading and inform yourself on the units of measurement and the best way to pick a space heater.

What Is BTU?

BTU stands for British Thermal Unit and is used to measure the power of HVAC appliances. It is a metric that measures the energy in the unit. One BTU gives the unit enough power to change the temperature of one pound of water by one degree Fahrenheit.

The higher the BTU the more powerful the unit is and the larger space it will be able to warm up.

HVAC systems are measured in BTU to help people understand the energy consumption, so they purchase the proper units for their home or business.

What Is An Amp?

An amp is a unit used for measuring electricity. Amp is short for ampere and is the unit of measure for electrical current. The number of amps your unit uses to run will determine the electricity used, and what will show up on your electric bill.

How Many Amps Does A Space Heater Use?

The number of amps used by a space heater depends on the size of the unit. For example, a 1,500 BTU uses 12.5 amps of electric current to operate.

The number of amps needed also depends on the outdoor climate and where you are located. Colder places, like Alaska or Michigan, will probably need more power to heat the space.

This means the space heaters may use more amps than expected. Account for your location when calculating the best-size space heater for you.

Below is a formula for calculating how many amps a space heater will need to warm a room and run smoothly. You can use this to determine what size space heater you will need.

How to Calculate How Many Amps Does A Space Heater Use

Here is the formula for calculating how many amps a space heater will use:

Space heater capacity (BTU) = Energy efficient rating /Power (in Watts)

Knowing the EER, or energy-efficient rating, is necessary for calculating this. If this formula seems like a hassle, there are many places to find out what size BTU space heater needs what number of amps. It is often stated on the manufacturer’s website.

Bottom Line

how many amps does a space heater use
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Understanding how space heaters use energy and their capacity for power helps you choose the best space heater for your home or business. Hopefully, after reading this article you understand how space heaters are sized and how much energy they use so you can make the right choices.

Luckily, space heaters don’t use an exorbitant amount of electricity, so they can be plugged into almost any outlet in the US with no problems at all. But just in case you encounter a low voltage outlet, you are armed with the knowledge provided here.


How do I know what size space heater to use?

Many manufacturers put the capacity of the space heater right on the box to let you know how large of a room it will be able to warm up. A good rule of thumb is 10 watts of heating power for every square foot. This simple equation will help you choose the right size for any room.

If you are heating a space with very high ceilings, you may want to go up a size to be sure the entire room is warm, and all the heat doesn’t just rise to the ceiling.

How can I save energy when using a space heater?

The obvious way to save energy is to turn off your space heater once the space has warmed up enough. Space heaters don’t filter or recycle the air the way air conditioners do, so you can shut them off periodically and still keep the room comfortable and at an ideal climate.