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Stove Size Calculator

What Size Stove Do I Need to Heat My Room?

Just enter the dimensions of your room in the boxes below and our stove size calculator will do the rest. You'll see the recommended wood-burning stove heat output in kW for the space you want to heat.

How Does the Stove Size Calculator Work?

The stove size calculator takes the dimensions of your room and gives you a suggested stove heat output for the volume of space you need to heat. This is intended as a guide to point you in the direction of stoves with suitable heat outputs. But you might choose to adjust the results based on the specifics of your room. This could include variables like:

  • How well insulated your home is
  • Whether the room is open-plan or contains an open staircase
  • How draughty the room is

How warm you like the room — the calculator will suggest a heat output to comfortably heat your space to around 20°C

For a wood-burning stove to heat your home effectively, it also needs to be installed with enough space around it. Stoves work by heating the air around them, causing the air to rise and fill the room. If a stove is in an enclosed space, this convection process won't work properly. And if combustible materials, such as soft furnishings, wallpaper and furniture, are nearby it will also create a safety risk.

Learn more about how much space to leave around a wood-burning stove or call us on the number at the top of this page to discuss your stove installation.

What Is Output Power?

The heat output or output power of a wood-burning stove is measured in kilowatts (kW), just like other appliances such as electric fires and radiators. A stove's heat output is a guide as to how many kilowatts of heat it will pump into your room in an hour. If your stove has a 5kW heat output, it should generate around 5kW of heat every hour.

But this isn't an exact science. Stove manufacturers choose the heat output they want their stove to be rated at. The stove is then tested to demonstrate its efficiency at the declared heat output.

The result is that both the heat output and efficiency are impacted by many factors, including the type of fuel you're burning, how much fuel you add, how much air you allow into the stove, and the strength of the draw up the chimney. The actual output power produced by any stove will depend on how it's being operated.

Nominal vs Maximum Output Power

You might see nominal heat output and maximum heat output mentioned when browsing wood-burning stoves. Nominal output power is what we described above: the heat output designated by the stove manufacturer and the output at which it was being tested to determine its efficiency. Maximum output power is a better indicator of the maximum heat output you'll be able to get from a stove.

What Fuel Can I Use?

Stoves can be either wood-burning stoves or multi-fuel stoves. Although wood-burning stoves is often used as a catch-all term for all stoves, multi-fuel stoves can be used to burn smokeless fuels (such as anthracite) or logs, whereas wood-burning stoves can only be used to burn logs. All logs should be well seasoned before being burned, otherwise energy is wasted on evaporating moisture instead of heating your room.

Coal vs Wood Heat Output

Your choice of what to burn will impact the heat output of your stove. Green wood will burn less efficiently than dried wood, while different types of wood burn in different ways. Hardwood typically burns for longer than softwoods. But even the size and shape of logs changes how they burn.

Smokeless fuels are generally denser than logs, burn for longer and burn hotter, creating a greater heat output than logs. But seasoned wood usually delivers a better price per kilowatt hour (kWh) than smokeless fuels.

About Gr8Fires

We've been selling heating appliances for more than three decades and online here at since 2009. We use the knowledge we've built in that time to help you find the wood-burning stove that's perfect for your home. We pride ourselves on supplying high-quality woodburners and multi-fuel stoves at the lowest possible price to households throughout the UK.

Once you've used the stove size calculator, take a look at our full range of stoves to find appliances with the right heat output for your room. See our stoves.

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