BTU Calculator for Cast Iron RadiatorsBTU Calculator for Cast Iron Radiators

When choosing Cast Iron radiators some thought must be given to the heat output of the radiator and the room that you are going to place the radiator in. All our Cast Iron Radiators have different outputs which is detailed on our individual product listings. These heat outputs are measured in British Thermal Units or BTU's.
We also have a Panel Radiator Calculator if you need to work out the heat output you need to replace when changing your 60s and 70s steel panel radiators. Click here for more details.

Use the below calculator to determine the heat output you require for the room you intend to place your radiator.

Please enter the room details and dimensions in metres or feet. Your BTU requirement will appear below.

First, Enter Your Room Details:

Second, Enter Your Room Dimensions

Metres (m)   or   Feet (ft)
(m) or (ft)
(m) or (ft)
(m) or (ft)

Your BTU Requirement will appear below:

This is an estimated calculation based on the above information.

BTU (t=Δ30) BTU (t=Δ50) BTU Requirement
Watts (t=Δ30) Watts (t=Δ50) Watts Requirement