Dehumidifier Picker
Find the right size and type of dehumidifier for your room. Enter the room size, how damp it is and how cold it gets, and get a recommended capacity in litres per day with an estimated running cost.
No sign-up required. Enter your own electricity rate for a more accurate estimate.
PICK YOUR DEHUMIDIFIER
Find a suitable dehumidifier based on your room, moisture needs and how you plan to use it.
Your Room & Space
Tip: A typical bedroom is 12–16 m²; living rooms 20–35 m².
Moisture Sources & Dampness
Human breathing & perspiration adds ~0.3 L/day per person.
Drying a wet spin load indoors releases ~2.0 to 2.5 L of water.
Usage, Drainage & Running Cost
The unit cycles compressor on/off automatically as needed, cutting electricity waste.
Extraction Capacity Needed
Look for 12 – 16 L / day
Based on your room dimensions, dampness level, and moisture generation.
What you'll need
What to look for, not a brand: any dehumidifier with these ticks will do.
How it works
Size a dehumidifier from your room and your damp problem
The picker estimates how much moisture your space needs to lose each day, then matches it to the sizes dehumidifiers are sold in. It also suggests the right type for your room temperature and estimates the electricity cost. The sources and assumptions behind it are on our How we calculate page.
Your room
Enter the floor area and ceiling height. Bigger rooms hold more air and more moisture, so they need a larger unit. Rooms taller than 2.4 m are scaled up.
How damp it is
Pick the strongest sign you see: a stuffy feel, condensation on windows, a musty smell or visible mould. People and laundry dried indoors add to the moisture.
Temperature and use
Cold rooms need extra capacity and often a desiccant model. Your electricity price and how long the unit runs give the estimated running cost.
Examples
What size dehumidifier do common rooms need?
These examples use the picker’s own calculations. Size depends on the room, how damp it is and how cold it gets, and the type of unit has a big effect on running cost.
Illustrative only. Sizes are rated capacities (tested at 30°C and 80% humidity). Costs assume auto mode at about 7.5 hours a day and €0.30 per kWh. Actual moisture, run time and costs vary with the weather, ventilation, the model you choose and how you use it.
Understand your result
What can you do with your recommendation?
Use the recommended size and type as a starting point when you compare models. The right choice also depends on noise, drainage and where you will use it. Already have a dehumidifier? See what it costs to run with the Electricity Cost Calculator.
Compare like for like
Check the rated capacity in litres per day and the conditions it was tested at. Compare the power in watts too, as it drives the running cost.
Choose the right type
Compressor models are the most efficient in heated rooms. In cold garages or cellars, a desiccant model keeps working where a compressor would ice up.
Tackle the cause too
Ventilating while cooking and showering, drying laundry outside and fixing leaks all reduce how long a dehumidifier needs to run.
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Common questions
Frequently asked questions about dehumidifiers
Common questions about choosing the right size and type of dehumidifier for your home.
What size dehumidifier do I need?
It depends on the size of the room, how damp it is, how many people live there and whether you dry laundry indoors. As a rough guide, a bedroom with condensation needs around 8–10 litres per day, a larger living area 10–14 litres and a damp basement 20 litres or more. Use the picker for an estimate based on your space.
What does litres per day mean?
It is the most water a dehumidifier can remove in 24 hours under test conditions, usually 30°C and 80% humidity. In a typical home at around 20°C it removes much less, so the picker builds in extra capacity.
Should I choose a compressor or a desiccant dehumidifier?
Compressor models suit heated rooms and use less electricity. Below about 12°C they lose efficiency and can ice up, so a desiccant model is usually better in garages, cellars and unheated homes. Desiccant units use more power but give off a little warmth.
How much does a dehumidifier cost to run?
Multiply its power in watts by the hours it runs and divide by 1,000 to get kWh, then multiply by your electricity price. A 270 W unit running 7.5 hours a day uses about 2 kWh, or around €0.61 a day at €0.30 per kWh.
What humidity should I aim for?
Most homes are comfortable at 40–60% relative humidity. Keeping it below about 60% helps prevent condensation and mould. Setting the humidity lower than you need just uses more electricity.
Will a dehumidifier fix damp and mould?
It controls moisture in the air, which helps stop condensation and mould coming back. It will not fix leaks, rising damp or rain getting through walls, so get those checked if damp patches keep growing.
Are the results exact?
No. They are estimates. Actual moisture levels, run times and running costs vary with the weather, ventilation, the model you choose and how you use it.