Heating and heat loss calculator Heating and heat loss calculator

Room heat loss calculator

Use for first-pass radiator, convector or heater sizing.

A full heat-load design should consider walls, insulation, ventilation and thermal bridges.

Use the calculator to turn input values into a clear, repeatable result.
Keep units and assumptions visible so the calculation can be checked later.
Copy the result or key numbers for reports, messages or spreadsheets.
Reset to defaults when you want to compare another scenario from a clean state.
Calculators run in the browser and are useful for quick estimates before formal checks.
For finance, health, engineering or legal decisions, verify important results with a specialist or official source.