Basic Heat Calculator

Use our Basic Heat Calculator to give a rough estimate of the heat requirements for your room.

Room type

What sort of room is it?


Length (meters)
Width (meters)
Height (meters)

Additional factors

Is the room North facing?
Does the room have French windows?
Does the room have double glazing?
Estimated total: 0 Watts (0 BTUs)

Three Tools in One

  • Basic Heat

    Use this heat calculator for a rough idea of how much heat you need. It uses a tried and tested method based on the volume of the room - best for a quick estimate.

  • Advanced Heat Calculator

    Use this for a comprehensive heat loss calcuation that takes into account most parameters that affect heat loss in a room. This method takes a little longer to complete but is fully customisable - you can alter all values.

  • Panel Radiator

    Use this tool to find out how much heat your existing radiators emit. Great if you'd like to replace panel radiators with cast iron radiators!