Gasoline Portable Generator

Space heaters are a miracle in chilly homes. When the winter weather comes, sometimes the cold can seep into your space and cause you to reach for the fleece blankets. Space heaters can come in handy during an outdoor party or inside your camping tent. But how can you use a space heater without an outlet? Find out what size generator to run a space heater you need to keep these appliances saving you from the cold.

Can a Generator Run a Space Heater?

Yes, you can run a space heater using a generator. It depends on the size of the space heater and the size of the generator, but following some safety guidelines, you can successfully run a space heater.

The most common reason to run a space heater on a generator is because of a power outage, a camping trip, or other outdoor activity like watching fireworks or having a barbecue. It can ruin a fun event if you are shivering the entire time.

Short Answer

The average size generator needed is 2000 watts, but many factors can change this. To understand the best size generator for your needs, read the factors to consider below.

Factors to Consider

There are a few factors that change the size generator you will need, so consider these when choosing a generator.

Space Size

This refers to the size of the area you are trying to warm, whether it’s inside your house or in an outdoor area. The larger the space, the more powerful a space heater you need, therefore a more powerful generator.

Heater Location

Space heaters will still help warm you up when outdoors, but it is extremely easy for heat to escape. If you are using a space heater completely outdoors, you may feel it isn’t warming up as much space as it does when used inside.

This is because there are no doors or walls to stop the heat from escaping, but using a heater outdoors will still keep you warmer than having nothing.

Coverage Capability

The coverage capability is the amount of square footage a space heater can heat up. If you place a small space heater in a large space, the heat will disperse too quickly, and the room won’t be warm and cozy.

Space heater coverage capabilities range from 25 to 400 square feet. And the wattage needed ranges from 250 watts to 4,000 watts. A good rule of thumb is to have 10 watts of generator power for every square foot your space heater will warm.

Safety Tips

Here are some safety tips to keep in mind whenever you run a space heater off a generator, or whenever you use a generator in general.

  1. Generators produce deadly carbon monoxide, so never use them indoors. Always keep your generator outside and away from open windows.
  2. Stay at least 2-3 feet away from the generator while it’s on.
  3. Never run a generator while you sleep or are not present.
  4. Never leave a generator running alone with children.
  5. The space heater should only be run for one hour at a time to avoid tripping a circuit or overheating wires.
  6. Use a timer to turn the space heater on and off.
  7. Make sure all rooms near your generator have a working smoke alarm installed.
  8. Do not run other electrical appliances along with the generator. This may overload the heater and cause serious problems.
  9. Keep all children and pets a safe distance away from the generator as well as any of its cords or wires.
  10. Be ready to shut off power at the main breaker, in case something goes wrong with the generator, and it starts to smoke, spark, or smell like fire.
  11. Store all fuel tanks outdoors where they likely will not leak.

Bottom Line

what size generator to run a space heater
Source: Shutterstock

Luckily, you can use a generator to run a space heater and keep you toasty and warm. But it isn’t that simple. You need to know the correct size generator to use for your space heater. Hopefully, this piece has given you a firm idea of the safest and most successful way to use a generator to power your space heater.

While space heaters are a wonderful appliance to keep you and your family comfortable, they come with potential risks. You must follow the safety tips and any manufacturer instructions so you can be warm and safe at the same time.

Remember to keep the generator outside at all times and give your space heater a break every few hours. And enjoy staying warm and cozy wherever you go!


What is the maximum wattage for a space heater?

The maximum wattage for a space heater is typically 4,000 watts. This is the maximum wattage and is usually a large space heater used for large spaces.

Is it safe to power a space heater with a generator?

Yes, it is safe to use a generator for a space heater as long as you follow safety guidelines. The generator should never be inside the house or near a window because they produce carbon monoxide.

What size inverter do I need to run a 1500 watt heater?

If you want to use a 1500 watt space heater, you will need a 1500-2000 watt inverter.

How much electricity does a small space heater use?

A small space heater, such as a 1500 watt space heater, will use 1.5 kilowatts of power every hour.