Radiator Size Calculator

Radiator Size Calculator helps you figure out what size radiator you actually need, without overcomplicating it.

You can either get a quick estimate in seconds, or take a bit more time and set up your room properly for a more accurate result.

It’s built around typical UK homes, so the numbers you get are practical and useful.

== What you get ==

Free to use
• Quick Calculate for fast radiator sizing
• Instant BTU and wattage estimates

Full Access (one-time purchase)
• Guided room setup with step-by-step help
• Save multiple rooms
• Export your data as text or CSV
• More detailed, tailored results