What size dehumidifier do I need? How to pick the best size to get the job done

With so many dehumidifiers on the market, we’ve got the low-down on what size you actually need for your space

Russell Hobbs 20 litre dehumidifier in hallway
(Image credit: Russell Hobbs)

‘What size dehumidifier do I need?’ is a question many people are asking themselves. And it’s a valid question, too. Choosing the right size dehumidifier is essential if you want to make the most of its moisture-removing qualities. 

After all, there’s a reason why the best dehumidifiers are becoming some of the most popular appliances in the UK. Amidst the wet weather, the condensation in our bathrooms, and our struggle to dry our clothes in the winter, the humble dehumidifier can restore order in our homes - and maintain the ideal humidity of a room

But with so many shapes, sizes, and styles of dehumidifiers on the market, it can be hard to know what will work for your home… and what won’t. To help you out, we’ve consulted with dehumidifier experts to help you choose the right size dehumidifier. 

Russell Hobbs RHDH1061 Portable Dehumidifier

(Image credit: Russell Hobbs)

 How big of a dehumidifier do I need? 

So, what size dehumidifier do you need? In short, it all depends on your problem areas and how big those areas are.

Small rooms

white dehumidifer in home

(Image credit: Quiet Mark)

It’s not uncommon for smaller rooms, such as the kitchen or the bathroom, to suffer from humidity the most. These rooms normally pump excess moisture into the air when you shower or when you cook. 

If you want to stop mould from developing a dehumidifier with an extraction rate of around  10 to 14 litres per day would suit these kinds of rooms, as long as your room is under 400-square-foot. 

But what does this 14-litres mean? Chris Michael from Meaco revealed, 'When choosing the right sized dehumidifier for your home, it is the amount of water the dehumidifier can extract which is the important figure, not the capacity of the water tank.'

Russell Hobbs RHDH1001 10 Litre/Day Dehumidifier |£119 at Amazon

Russell Hobbs RHDH1001 10 Litre/Day Dehumidifier | £119 at Amazon
The Russell Hobbs 10L dehumidifier has a good-sized capacity for most homes at a budget-friendly price point.

Medium rooms

If you have a room between 400 and 800-square-foot, such as a living room or bedroom, you’ll need a slightly larger dehumidifier. 

Tech expert Andhi Ermawan from My Pros and Cons says, 'Remember, these are rough guidelines, and other factors like relative humidity, the number of occupants, and specific damp issues may require adjustments.' However, a dehumidifier that extracts around 20 to 25 litres per day should do the trick.

Russell Hobbs RHDH2002 20 Litre/Day Dehumidifier | £149.99 at Amazon

Russell Hobbs RHDH2002 20 Litre/Day Dehumidifier | £149.99 at Amazon
This 20L option comes in significantly cheaper than the comparative Meaco model. On the flipside, it does use more energy, has a lower capacity tank, and it's not the quietest model. 

The whole house

In rare cases, moisture and condensation problems aren’t limited to one or two rooms in the house. It’s important to get rid of damp as soon as you can, but this can be difficult when you have a whole house to contend with. And while you could buy separate dehumidifiers for each room, you could also invest in a whole-house dehumidifier. These normally have a daily extraction rate of around 40 litres - but they can be noisy. 

Katie Holland, Marketing Manager for Russell Hobbs, says, 'It’s also important to consider the noise level of a dehumidifier, especially if you’re planning to use it in your living space. Whilst all dehumidifiers generate a certain level of noise, lots of models contain a low noise motor to ensure minimal disturbance whilst in use.' 

Pro Breeze® 30L/Day Dehumidifier |£239.99 at Amazon

Pro Breeze® 30L/Day Dehumidifier |  £239.99 at Amazon
This Pro Breeze option can suck a whopping 30 litres of moisture from the air per day. It's big, heavy, and expensive, but if you want a powerful machine then this unit is well worth snapping up whilst reduced.

Tips for choosing the right size dehumidifier for your home

While the above information is a good jumping-off point, determining what size dehumidifier you need doesn’t always have a one-size-fits-all answer. Below, you’ll find a few tips on how to choose the right size dehumidifier for your house. 

Measure the humidity: Although dehumidifiers are a popular appliance, there’s no point in buying an appliance you don’t need. To determine this, you can measure the humidity of your home using something like this ThermoPro TP49 Small Digital Hygrometer from Amazon. You can then compare it to the ideal humidity for a room and then choose the right size accordingly. Of course, if you’re really struggling with dampness, choosing the right size is essential.

Decide its purpose: When choosing the right size dehumidifier, you need to consider the purpose of this appliance. Are you buying a dehumidifier to maintain a constant humidity level? Are you using a dehumidifier to dry clothes? Are you using a dehumidifier to help you sleep better? Our guides on how to choose a dehumidifier to dry clothes and how to choose a dehumidifier for the bedroom can help you out. 

Understand your home: Whether you have a small home or a big home, there are bound to be some areas of the house that struggle more with condensation and excess moisture. This is usually the bathroom, kitchen, and bedroom. But if these are the only problem areas, you probably don’t need a dehumidifier that can tackle the whole house. Instead, you may be better off buying a smaller dehumidifier - and perhaps one that has wheels so that it can be moved around the house.

Consider the cost: Dehumidifiers come in all kinds of shapes, sizes, and prices. But generally, the larger they are (and the higher the extraction rate), the pricier they are. This is where you have two options to choose from: you could either opt for one large dehumidifier to tackle the whole house, or you could opt for a number of smaller dehumidifiers to tackle individual rooms. The price of these two options will vary depending on the size of your house, so it’s best to do some sums before parting with your money. 

meaco dehumidifier in laundry room with basket of clothes

(Image credit: Quiet Mark)


Do dehumidifiers use a lot of electricity?

Like any appliance, a dehumidifier will, of course, use more electricity than what you’re used to. However, how much a dehumidifier costs totally depends on the size of the appliance, how often you use it, and the efficiency of the appliance itself. On average, though, a 12-litre dehumidifier with a wattage of 157w will cost you just under 5p an hour.  

How large of a dehumidifier should I get?

Chris from Meaco says, 'There are a lot of other factors that need to be considered as well, such as how many people live in the home, how you dry your laundry and whether you have any pets.' 

But the best way to know how big of a dehumidifier you need is to check the humidity in your house. By measuring the humidity room by room, you can determine whether you have a small condensation problem that could be solved by opening a window or a bigger problem that requires the help of a dehumidifier.  

Hopefully, you’re now equipped with all of the information you need to choose the right size dehumidifier for your home.  

Lauren Bradbury

Lauren Bradbury is a freelance writer and major homes enthusiast. She graduated with a Bachelor’s degree in English and Creative Writing from the University of Chichester in 2016, before dipping her toe into the world of content writing. After years of agency work, writing everything from real-life stories to holiday round-ups, she decided to take the plunge and become a full-time freelancer in the online magazine world. Since then, she has become a regular contributor for Real Homes and Ideal Home, and become even more obsessed with everything interior and garden related. As a result, she’s in the process of transforming her old Victorian terraced house into an eclectic and modern home that hits visitors with personality as soon as they walk through the door.