Dry Home Advice Interactive calculator
What size dehumidifier do I need?
Enter the room size and moisture problem. We’ll estimate the capacity band to compare first, plus whether a compressor or desiccant model makes more sense.
How to choose a dehumidifier: three checks before sizing
- Start with room temperature. Select heated or cold below. For an unheated space, compare cold-room options before choosing on capacity alone.
- Measure the room size. Enter length, width and ceiling height in metres for the space you want to treat. This tool estimates a starting capacity band, not a whole-home performance guarantee.
- Allow for moisture and laundry use. Choose the condensation level and whether you dry clothes indoors. For regular washing loads, use the laundry buying guide alongside the result.
Calculate below, then compare noise, running cost and tank size in the UK dehumidifier shortlist. The right size is a starting filter, not a product recommendation.
How to use the result
Use the litres-per-day band as a shortlist filter, then compare noise, running cost, tank size and whether the room is warm enough for a compressor model.
Cold rooms
Garages, conservatories and unheated utility rooms often suit desiccant dehumidifiers because compressor units lose performance as temperatures drop.
Laundry rooms
Indoor laundry can push a room into a higher capacity band because wet clothes release a lot of moisture before they feel dry.
Ready to compare products?
If the calculator points to a normal heated room, start with the UK ranked shortlist. If it points to a cold room or laundry-heavy use, use the specialist guides first.
