BTU Calculator BannerChoose and enter in the appropriate values in the form. Then click 'Calculate Requirements' to get your room's BTU requirements. Please note, this is a guide only. A radiator with insufficient output may never raise the temperature to that required. Outdoor temperatures, external walls, insulation, heated adjacent rooms (i.e. above, below and to the side) all play a part.

The boiler should be sufficient to supply all connected radiators to the sum of their maximum demand. Larger rooms such as Living Rooms may require more than one radiator positioned evenly throughout the room. If this is the case, divide the required output between the number of radiators needed.

What is the length of the room?  metres
What is the width of the room?  metres
What is the height of the room?
What floor type do you have?
What room are you calculating?
Do you have double glazing?
Is any wall in the room north facing?
Do you have french windows?
How many walls are outside walls?
How warm do you like your house?

The BTU calculator should only be used as a guide.