ROOM HEAT OUTPUT
Radiator BTU calculator
Estimate radiator output from room dimensions and insulation adjustment.
Estimated result
5159 BTU/h
- Output
- 1512 W
- Room volume
- 33.6 m³
A sizing estimate. External walls, glazing, location and flow temperature require a room-by-room heat-loss survey.
SOURCES & REVIEW
Checked against official guidance
Last checked 14 July 2026 · Rule version GB-2026.27.1
Energy Saving Trust: Heating ↗COMMON QUESTIONS
Frequently asked questions
Is this an exact quote or tax return?
No. It is an estimate based on the inputs and assumptions shown.
When was this checked?
The method and linked official guidance were reviewed for the current UK release.