Finding the right radiator size is essential for keeping your home warm and energy-efficient. Our easy-to-use BTU calculator helps you work out how much heat output your room needs, so you can choose a radiator that’s both stylish and powerful enough to keep you comfortable all year round.

What is a BTU?

BTU stands for British Thermal Unit. It’s a standard measurement of heat output. The higher the BTU, the more heat a radiator can give off. By calculating your required BTUs, you make sure your radiator isn’t too small (leaving your room cold) or too large (wasting energy and money).

How to Use the BTU Calculator

  1. Enter your room dimensions (length, width, height).

  2. Select details such as windows, insulation, and room type.

  3. Click calculate to see the recommended BTU output.

Our tool instantly tells you the ideal BTU requirement, making radiator shopping simple.

Why Calculating BTU Matters

  • Comfort - ensures your room heats evenly.

  • Efficiency - avoids wasting energy and lowering bills.

  • Accuracy - helps you pick the right radiator first time.

Shop Radiators by BTU

Once you know your BTU requirement, you can browse our full collection of radiators by size and style. From sleek vertical radiators to traditional column designs, The Radiator Hub has options to match your décor and heating needs.