When selecting cast iron radiators, it’s important to consider both the heat output of the radiator and the size and purpose of the room where it will be installed. Each of our cast iron radiator models has a different heat output rating, which you’ll find listed on the individual product pages. These ratings are measured in BTUs (British Thermal Units).

If you’re replacing older steel panel radiators from the 1960s or 1970s, we also provide a Panel Radiator Calculator to help you determine the equivalent heat output you’ll need. [Click here] for more details.

Use the calculator below to estimate the BTU requirement for the room where you plan to install your radiator. This will help ensure you choose the right size radiator for comfort and efficiency.