Dehumidifier Size Calculator
Free toolBefore buying a dehumidifier, calculate the liters/day capacity you need based on the room size and how humid it is.
Result
How to use it
- Enter the floor area of the room.
- Choose the humidity level: moderate, high or very high.
- Read the recommended extraction capacity in litres per day.
What it works out and how
The tool assigns a base capacity in litres per day according to the area and multiplies it by 1 for moderate humidity, by 1.3 for high and by 1.6 for very high. The result is the rated extraction to look for on the spec sheet. Advertised litres per day are measured in warm, humid lab conditions; in a cool house real performance is lower.
Frequently asked questions
How do I know my humidity level?
With a hygrometer, which costs very little. Between 40 and 60% relative humidity is comfortable; condensation on windows or mould patches point to a high level.
Compressor or desiccant?
Compressor units perform better in mild rooms. Desiccant units work better below about 15 °C, as in garages or basements.
Can it dry laundry?
Yes. Many models have a dedicated mode; in that case choose a capacity somewhat above the calculated one.