One of the most common questions we're asked by parents is:
"Should I buy my kid's waterproofs a size bigger?"
It's an understandable question. Children seem to grow overnight, and nobody wants to buy outdoor clothing they'll outgrow after a few months.
The good news is that, unlike everyday clothing, most children's waterproofs are already designed with growing room built in.
In this guide we'll explain how children's waterproof sizing works, whether you should size up, and how to make sure your child stays comfortable whether they're heading to forest school, nursery or simply enjoying family adventures outdoors.
Here's our video explaining how to buy the right size of kids waterproofs.
The Short Answer: No, You Usually Don't Need to Size Up
In most cases, we recommend buying waterproofs in your child's current height rather than sizing up.
Quality children's waterproofs are designed to be worn over normal clothing and often include:
- Extra room for layering.
- Adjustable features that grow with your child.
- Plenty of space for movement.
Buying the correct size gives your child the best balance of comfort, protection and longevity.
Ignore the Age – Focus on Height Instead
One of the biggest mistakes parents make is shopping by age. You'll often see waterproofs labelled something like:
- Age 4–5 years
- EU Size 110
The important number is actually the 110.
That means the waterproofs have been designed for a child who is approximately 110cm tall.
Because children grow at different rates, height is always a much more reliable guide than age.
If you're unsure, simply measure your child's height before ordering and choose the size that matches.
Why Waterproofs Already Have Growing Room
Parents are often surprised when new waterproof dungarees seem a little roomy.
That's completely intentional.
Children need space to:
- Squat.
- Climb.
- Crawl.
- Sit comfortably.
- Wear warm layers underneath during colder weather.
A slightly looser fit gives children complete freedom to move while helping the waterproofs last longer as they grow.
Adjustable Straps Mean They'll Last Longer
One of the biggest advantages of waterproof dungarees is the adjustable shoulder straps.
As your child gets taller, you can simply lengthen the straps, giving you much more wear than you might expect.
That's why buying the correct size often lasts just as long as buying bigger—without the discomfort of oversized clothing.
When Might You Consider Sizing Up?
There are a few situations where sizing up can make sense.
For example:
- Your child is right at the very top of the recommended height range.
- They're going through a particularly fast growth spurt.
- You're buying well in advance for next season.