Static sizing chart

Dehumidifier size chart UK

This chart gives a practical starting point for choosing a dehumidifier capacity. It is not a damp survey, but it helps avoid the common mistake of buying a unit too small for laundry, cold rooms or several damp spaces.

Quick takeaway

Match capacity to the problem, not just the room

A small heated bedroom and a laundry room of the same size do not need the same shortlist. Moisture source, temperature and daily use matter.

Use the calculator

Room/useTypical sizeMildModerateHeavy/laundry

Box room / wardrobe areaUp to 8m²Hygrometer or passive absorber firstSmall electric unitCheck source; avoid under-sizing

Bedroom8–16m²10–12L class12L class12–20L or investigate source

Flat living area16–30m²12L class12–20L class20L+ or multi-room plan

Laundry / utility8–20m²12L class20L+ or desiccant if coldHigh-capacity model

Garage / conservatoryVariableMeasure temp + RHDesiccant shortlistFix leaks/ingress first

When to size up

Indoor laundry: wet clothes add a lot of moisture, so size up if you dry clothes indoors often.
Multiple connected rooms: treat the open area as one larger space or focus on the worst room first.
Cold spaces: consider desiccant models rather than only chasing headline litres.
Persistent wet patches: check for leaks, rain penetration or structural damp before buying larger machines.

Turn the chart into a shortlist

Once you know the likely capacity band, compare product types and running costs before checking Amazon prices.

Use buyer finder Check running costs