Heating Calculator

Heating Calculator

If you’re not sure which radiators you need, our Heating Calculator can help predict the appropriate heat output required to keep a room at a comfortable temperature.

If you already know what size radiators you need, please visit our Radiator Finder page where you can search by radiator height/width and output.

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Please complete all fields carefully for the most accurate results*
Simply enter the details of the room you would like to heat as best as you can. Once the heating requirement has been determined, we’ll show you a list of radiators that will generate enough heat output to keep your room comfortable.

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Room profile

Sources of heat loss

Why radiator size is important


Choosing the right radiator can help reduce energy bills, for example too large a radiator will increase bills unnecessarily, but too small a radiator will be too cold and will be constantly running at maximum. By performing a Heat Loss Calculation, you can establish the radiator Watt / BTU outputs required for a particular room taking into account any heat that will be lost through walls, windows and ceiling. This ensures that your rooms will be heated comfortably and efficiently.

*Please note: Heat Loss Calculations are only estimated and are based on information you provide. The Heating Calculator can only process the most common factors that affect heat loss and may not take into account all factors relating to your particular requirements. Therefore any results provided by the Heating Calculator should not be considered 100% accurate, and we accept no liability for any errors resulting from the estimates given.

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