Heat Requirement Calculator

What Size Of Cast Iron Radiator Should You Choose?


With so much choice, it can require a lot of thought to choose the perfect cast iron radiator that looks great in your home. In addition, you will also need to make sure that it is capable of producing enough heat to keep you warm. Our cast iron radiators are built around your needs and thankfully there’s a standard way to calculate your room’s heat requirement. Based on the size, use and insulation of your room we can calculate the BTU (British Thermal Units) heat requirement that it requires.

To use our handy calculator, simply enter the dimensions of your room in metres, tell us the type of room and we’ll do the rest. We can then use this BTU number as a starting point to help pick you the perfect-sized radiators.


A selection of different heights and sized cast iron radiators against a white brick wall. The radiators are muted, classic colours

An original purple coloured Princess cast iron radiator . The radiator is in a wood panelled bathroom with a purple cast iron bath