How to choose a kids' mattress – here's what to look for

Want to make sure they get a good night's sleep? Here's what to consider when buying your child a mattress

Three young girls sat in bed laughing
(Image credit: Monstera from Pexels)

A good night’s sleep isn't just important for children’s development, it’s essential. Children’s bodies are still physically developing: toddlers, for example, can grow up to 1.5cm in a single night. This means they need more sleep than adults; between 10 and 14 hours, depending on age. That’s because the body goes into ‘repair mode’ during this time, and so proper sleep is vital if your child is to develop healthy bones, muscles and joints. 

It’s not just about physical growth, either. Studies have shown that when kids get good sleep it improves their behaviour, memory, ability to learn, and general mental and physical health. Not getting enough sleep, in turn, can lead to behavioural issues, child obesity, high blood pressure, and mental health problems. 

Even if you get all these things right, though, an unsuitable mattress can still cause problems. The best kids' mattress isn't as simple as sizing down on one of the best mattresses for adults. To that end, here are the main things you need to consider in choosing the right mattress for your child.

1. Stage of life

Baby sleeping

(Image credit: Monstera from Pexels)

The first and most obvious point is that your child will need a series of different beds as they grow and develop, and each will need a mattress specifically sized for that bed.

Your baby's first mattress will be a cot mattress. They'll then move from a cot to a bed between 18 and 36 months. There’s no strict rule about when that should happen. But it’s probably a good time if your child has started climbing out of the cot, or if they’re toilet training and need to get to the toilet easily during the night.

At this point, you can either move your child to a single bed, or what’s known as a toddler bed. This is a smaller ‘halfway house’ bed, which typically measures 70 x 140cm compared to a standard UK single bed size of 90 x 190cm. 

Another option is to spend a transitional period where your child sleeps on their cot mattress, or a single bed mattress, on the floor. This can prevent them falling, and make them feel safer at night.

2. Firmness

Your child’s spine is constantly growing. So it’s vital that it’s kept in a neutral sleep position – what’s known as good spinal alignment – during the night. For this reason, experts generally recommend a medium to medium-firm mattress for children. A soft mattress will not align their body properly, while firm mattress may be too uncomfortable for them to get a good night's sleep.

There’s also a practical reason to back up this choice. Like it or not, children don’t just use their beds for sleeping but also for jumping, bouncing, fighting, building forts, and more. And a soft mattress is going to withstand such a battering for much longer.

That said, firmness does ebb over time. And so, although many of us will have slept on a second-hand or hand-me-down mattress as kids, you really should make buying a new one a priority. Put simply, an old and sagging mattress will lack sufficient firmness for good spinal growth and good sleep quality overall. 

Moreover, it’s recommended that you replace a child’s mattress every three years for three- to 10-year-olds, and every five years for 10- to 16-year-olds.

3. Bed wetting

The Little Green Sheep Organic Waterproof Crib Mattress Protector

(Image credit: Little Green Sheep)

It’s common for children under five to wet the bed, and it can take some time for a them to learn to stay dry throughout the night. The best way to protect your mattress from bed wetting is to add a waterproof mattress protector. For cribs and play mats, for example, we recommend the Little Green Sheep Organic Waterproof Crib Mattress Protector

Mattress protectors have an elasticated skirt that neatly wraps around your mattress to protect it. A good one will feature three layers – an absorbent layer, a waterproof layer, and a top layer for comfort – and be easily removable and machine-washable.

4. Materials

What materials should your child’s mattress be made of? Opinion is divided on this, and so there's no universally agreed answer to this question. 

Many experts believe that a sprung mattress is the best for providing good spinal alignment for your children, as well as being cooler and more breathable. Pocket sprung mattresses are more supportive, and therefore preferable, compared with cheaper open-coil mattresses.

If your kids tend to toss and turn a lot, however, a memory foam mattress may be better than a sprung one, as this material will keep them in a more stable position during the night. Another reason to avoid sprung mattresses is if your child suffers from allergies (although this could alternatively be mitigated by adding an antibacterial mattress protector). 

Moreover, if your child gets hot at night, latex may be a better alternative than memory foam, despite being more expensive, as it is more breathable and naturally temperature-regulating. 

Other mattresses, meanwhile, combine multiple fillings to get the best of both worlds. For example, the Woolroom Junior Mattress offers the support of pocket springs with a wool layer that's naturally temperature regulating.