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BTU Calculator

BTU Calculator for sizing of radiators

Please feel free to use our free BTU calculator & radiator sizer. Enter your room information in the boxes below and press "Calculate" to find the recommended minimum size of radiator for your room. As with all heat loss btu calculators, assumptions are made about your room, as such this utility should only be used as a guide. All dimensions should be entered in metres.

Room Width : Select No. of External Walls  
Room Length : Select No. of External Walls  
Room Height :   
Windows & Doors Area :

Select Glazing  or

u-value :  


Select Wall Type or

u-value :  


Select Floor Type  or

u-value :


Select Above Ceiling or

u-value :

Calculated Heat Loss : W ( BTUs)
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