Heat Output Calculator

Choose and enter in the appropriate values in the form below. Then click “CALCULATE” to get your room’s BTU requirements.

Please note, this is a purely meant as a guide only. Radiators and heated towel rails with insufficient output may never raise the temperature to that required. Factors such as outdoor temperatures, external walls, insulation and heated adjacent rooms all play a part.

Radiator Heat Output Calculator

Please select your room and window type directly below followed by how sheltered your house is from the outside elements. Then proceed to the next row of boxes.