Room Heating Calculator (BTU / Watts)

Visit for an online BTU and Watts calculator for all our heated towel rails and electric heaters.

You will need to know the measurements and insulation properties of the room your are heating.


What is a BTU?

The British Thermal Unit (BTU) is a measurement of heat output, commonly from a central heating radiator or heated towel rail. The BTU output that you will require is dependant on factors such as the size of your room, the number and type of windows and what the room is used for.

If your room is quite large, and you have a high BTU requirement, you may wish to consider several radiators to meet the heating requirement of the room.

How do I choose the right panel heater / heated towel rail / designer radiator?

The BTU or Watt value of all our heating products is listed in the product descriptions, helping you select the products that meet your requirements. Our heated towel rails and designer radiators are listed in BTU’s. Our electric heaters (panel heaters, oil filled electric radiators) are listed in Watts.