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Radiator Calculator
What radiator size do I need?
With our radiator size calculator, you can quickly find out how much heating power your room requires. Simply enter the area, building type, room usage and optionally a safety buffer – we’ll calculate the required wattage.

Learn more in the matching guide:

What radiator size do I need?

Too small means too cold. Too large means wasted energy. This guide helps you calculate the right radiator size for your room – clearly and easily.
Good to know: For poorly insulated buildings or very cold regions, plan an additional 10–15% buffer to ensure comfortable warmth.

FAQ

How is the required heating power calculated?
Our calculation is based on room area, building insulation quality, room type and desired temperature. An optional safety buffer can be added.
Why does the building standard matter?
Well-insulated new buildings require much less heating power compared to older or poorly insulated homes.
How does the room type affect heating needs?
Rooms like bathrooms or hobby spaces need more watts per m² compared to bedrooms or hallways.
What is a safety buffer?
A buffer accounts for extremely cold days, poor insulation or large window areas – ensuring comfort even in tough conditions.
How do I select matching radiator sizes?
Our tips help you translate the required wattage into standard radiator sizes – such as 600 W or 1000 W models.

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