Radiator BTU calculator

BTU Radiator Calculator - Calculate your heating requirements

The heat output or 'BTU' (British Thermal Unit) calculator is a great way to work out how much radiator power you need. There are several factors which can affect this, such as room dimensions, heating levels and types of window, which are all covered in our radiator BTU calculator. Please note: You may need several radiators for bigger rooms.

Our BTU (British Thermal Units) calculator will help you to work out the heat requirement for your room, and recommend the number of radiators you will need to comfortably heat it.

What is a BTU?

A British Thermal Unit (BTU) is a measure of heat output from a radiator. Depending on the size of your room, the number and type of windows and what the room is used for, you'll need more or less heat. If you have a higher BTU requirement, it might be better to use more than one radiator to deliver the heat you'll need to a room. The total BTU output of several smaller radiators may meet your needs.

How do I choose the right radiator?

The BTU value of all our radiators is clearly labelled in-store and online, helping you find those which suit your requirements.

Step 1: Which room you are heating?
Step 2: What are the dimensions of the rooms?
Are you measuring in metres or feet?:
Length of room

Please enter the length of your room in your chosen units (metres or feet)

Width of room

Please enter the width of your room in your chosen units (metres or feet)

Height of room

Please enter the height of your room in your chosen units (metres or feet)

Step 3: What type of windows or doors are in the room?
Select all that apply:

Step 4: View your results

Your BTU result

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