Welcome to RadSizer - The Online Radiator Size calculation tool. By completing the form below and clicking the submit button the calculator will take the information supplied and provide a guide to the output required in Watts for a room. The calculator has been designed by active CORGI registered plumbers who were spending a lot of their time working out the calculations manually.


Room Use *
Room Length (m) *      Outer Walls      Neighbour Walls
Room Width (m) *      Outer Walls      Neighbour Walls
Room Height (m) *
Floor
Outer Wall      Cavity      Inner Wall
Roof
Windows
Window 1 Length (m)
Window 1 Height (m)
Window 2 Length (m)
Window 2 Height (m)
Window 3 Length (m)
Window 3 Height (m)
Design Temperature (C) *
Outside Temperature (C) *
Exposed Location
Intermittent Heating (%)






SIMPLE CALC


Please note that although this radiator calculator uses industry standard formulas, the results are for guidance only and we make no guarantees as to the accuracy of individual results.