Knowledge Base

How Many Watts Does a Space Heater Use? (Power Consumption Test)

By:Michael Johns

space heater power header

On this page, you will find out how many watts a space heater draws.

In the last few days, I’ve been working out the best way to heat my home. With energy prices increasing and attempting to use more sustainable energy sources, my attention quickly turned to a space heater.

It’s a super handy device I use to heat a single room rather than running the central heating. Plus they’re super portable so can be used in small spaces like RVs and semi-trucks. But what’s the power consumption actually like?

Below we will discuss and test space heater wattage, explain how to work it out for yourself, and calculate the total electricity required.

How Many Watts is a Space Heater?

The average space heater uses between 1500 – 2000 watts.

The exact number depends on the size and model of your space heater. The majority of portable space heaters use a maximum of 1500W, while the largest can peak at 2000W. 

This power rating is when you are running at the highest heat. If you use a lower setting you will be able to reduce the power level by around 500W. Plus if you turn the heat off and just use the fan setting it draws less than 30W.

There’s two components drawing electricity in your space heater. The main thing is the heating element which accounts for 90% of the power. Electrical heating elements are one of the highest electricity consumers in your home, you’ll also see them in hairdryers, kettles, and toasters.

Adding to this, space heaters use small AC motors to spin fans. This uses a small amount of power around 15W to 20W.

How to Find Out Your Space Heater Wattage

There’s 3 ways you can work out the wattage of a space heater.

  1. Check Product Specification

The quickest way is to look at the space heater’s specification. The watts (W) is usually written on a sticker on the base of the appliance. If not, you can check the user manual or the manufacturer’s website for technical details.

fine elemets heater power spec
  1. Use a Wattmeter

A wattmeter is brilliant for getting a live wattage reading and tracking total energy usage of any appliance. You can plug it into your space heater to get instant information. 

I used one to test my space heater which gave a live reading of 2052W.

space heater watt test
  1. Wattage Formula or Calculator

If you know the amperage and voltage of your space heater you can use this to find the maximum watt rating. Simply use the formula Amps x Volts = Watts. Or you can head over to the ‘Watt Calculator’ to work this out.

Space Heater Wattage Examples

Let’s take a look at specific examples of how many watts a space heater draws. Below is a collection of modern space heaters with their listed power ratings.

Space Heater ModelPower Rating (Watts)
Kismile Small Electric Space Heater1500
Aikoper Space Heater1500
BLACK+DECKER Portable Space Heater1500
GiveBest Portable Electric Space Heater1500
Dreo Portable Space Heater1500
Lasko 755320 Ceramic Space Tower Heater1500
F.EASY.D Space Heater1000
Oscillating Space Heater with Thermostat1500
AirNmore Comfort Deluxe with Copper PTC1500
Amazon Basics Ceramic Personal Heater1500
Igenix Flat/Upright Portable Electric Fan Compact Heater2000
Warmlite 2000 Watt Portable Electric Fan Compact Heater2000
Black and Decker Low Noise Ceramic Electric Fan Tower Heater 2000

As you can see, the power ratings vary between different space heaters. So you should take the time to check your own device.

How Much Electricity Does a Space Heater Use?

You can use space heater wattage to work out how much electricity it uses. Plus this can be helpful to understand how much it costs to run your space heater.

A watt (W) is a measurement of power at a single point in time. A watt-hour (Wh) is the total amount of electricity used in an hour. For example, a space heater drawing 1500W would use 1500Wh when running for an hour.

Electricity bills are recorded in kilowatt-hours (kWh). A kilowatt is simply 1000 watts. So a 1500W space heater running for 1 hour uses 1.5kWh.

Let’s say you use your heater for 2 hours a day. This means a space heater uses about 3000Wh or 3kWh electricity a day. That’s 90kWh a month and 1095kWh a year. 

That’s a rough electricity cost of $0.45 a day or $164.25 a year to run a 1500W space heater for 2 hours every day!

Using a Space Heater Off-Grid

If you’re planning to use your space heater in an off-grid situation like a power outage, RV, campervan, boat, semi-truck, or similar, this information is critical. You can ensure your electrical equipment has enough capacity and runtime.

You can either use a power inverter, portable power station, or generator to generate AC electricity. 

To make sure everything runs smoothly you should check two things on this equipment – wattage capacity and total energy capacity. 

Your power source, like an inverter, should have a wattage capacity of at least 20% more than your space heater. This ensures it will be able to deliver enough power as they are never 100% efficient. To give you an idea, you’ll likely need 2500W power output!

Secondly, you need to ensure your energy source, like a battery, has enough energy to run the space heater for the required amount of time. As we already know, it will use about 1500Wh electricity per hour. This is the equivalent to 125Ah on a 12V battery.

How Many Watts Does a Space Heater Use Summary

I hope you now understand how many watts a space heater uses.

It might look small but it packs a huge punch! If you run your heater for long periods of time then you’ll notice a spike in your electricity usage. There’s no way around the fact that the internal heating element guzzles a ton of power. It’s a bit like using a large hairdryer to heat a room! If you’re thinking about using one in your RV or on a camping trip then think again. A space heater will deplete a deep cycle battery or power station in less than an hour.