Heat Output Calculator

Calculate your room's BTU requirement

Enter your room details below, along with a name, and save it to your Wish List to keep it for easy reference.

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.

My Required BTUs

It is important to know how many BTU’s you require to heat each of your rooms. 

You can use our Heat Output Calculator to work this out, and save each room’s requirements.

Step 1 Enter Room Information

Step 2 Enter Room Dimensions

Please select whether you'd like to provide the room dimensions in metres or feet.