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.

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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: compare cold-room dehumidifier picks rather than only chasing headline litres.
Persistent wet patches: check for leaks, rain penetration or structural damp before buying larger machines.

What the litre bands do—and do not—mean

The table uses editorial starting bands, not manufacturer-certified room limits or a measured litres-per-square-metre formula. Moisture load, temperature, humidity, ventilation and connected rooms affect the result. We have not tested these bands in identical homes, and the chart does not alter the calculator’s sizing rules.

Manufacturer example checked 9 October 2026: Meaco’s Arete Two 12L extraction table lists 1.97 litres per day at 10°C / 60% RH and 5.40 litres per day at 20°C / 60% RH, compared with 11.99 litres per day at 30°C / 80% RH. Those are manufacturer-published figures for one model, not our test results. They show why a “12L” label is not a promise of removing 12 litres in your bedroom every day, and why equal-condition data matters more than headline capacity alone.

Turn the chart into a shortlist

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

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