Calculate the precise radiator output needed for any room based on its dimensions, glazing, and materials. Generate professional PDF reports for planning and documentation. All calculations are performed offline on your device.
1.1.1
October 7, 2026
You asked, we listened: you can now type room measurements directly, or fine-tune them with the new − and + buttons. PDF exports show your measurements exactly as entered. Plus general stability improvements.
More$2.99
Radisize Pro
Lifetime access to all Radisize features
Radisize is a utility app designed to calculate the correct radiator size (BTU and kW requirements) for individual rooms. It considers various room details like dimensions, glazing, and materials to provide accurate heating output needs.
Yes, Radisize is available for free. There are no subscriptions or hidden costs associated with using its core radiator sizing features.
No, Radisize is ad-free. The app focuses on providing a seamless user experience without any advertisements interrupting your calculations or reports.
Yes, Radisize is an offline-first application. All calculations are performed locally on your device, meaning you do not need an internet connection to use it.
Radisize can export professional PDF reports for an entire property. These reports detail the radiator requirements for every room, making them ideal for planning, quotes, and documentation.
Radisize considers room dimensions, external wall count, wall construction type, floor and ceiling types, glazing area and window type, safety factor, and the chosen radiator rating (ΔT35 or ΔT50).
Radisize is supported on iPhone and iPad devices. It is designed to work seamlessly across Apple's mobile and tablet platforms.
The latest version of Radisize is 1.1.1, which was last updated on October 7, 2026. Updates typically include improvements to features and performance.
