Kids' Swimwear: How to Choose the Right One by Age

Every summer, the same question comes up: which bathing suit should you get for your child? With so many styles, fabrics, sizes, and features to consider, it can feel overwhelming. But finding the right swimwear for your little one really does make a difference, both for their comfort and their safety. Here's a practical guide to help you navigate it all, from babies to teens.

Babies (3 to 24 Months): Prioritize Protection and Practicality

Babies have especially sensitive skin. At this age, a swimsuit needs to provide effective sun protection and make diaper changes easier, since those happen poolside too.

What to Look For

• UPF 50+ protection: essential for delicate baby skin. Long-sleeve rash guards cover the most surface area.
• Snap closures at the crotch: a small detail that makes a big difference when it's time for a change.
• Soft, quick-drying fabric: recycled REPREVE polyester, used in our collections, is ideal. It's lightweight, gentle on skin, and kinder to the planet.
• A one-piece silhouette: it stays in place during all that splashing and wiggling.

At Deux par Deux, our baby girl swimwear and baby boy swimwear are designed with all of this in mind: maximum protection, practical closures, and prints that little ones absolutely love.

Ages 2 to 5: Comfort and Freedom of Movement

Once kids hit age 2, they want to be fully in the action. Splashing, jumping, playing at the water's edge... their swimsuit needs to keep up.

Key Criteria

1. A snug but not tight fit: nothing should restrict movement, but the suit still needs to stay in place.
2. Secure straps or closures: a swimsuit that slips at every jump is nobody's friend.
3. UPF 50+ protection: kids this age can spend hours outside without realizing it.
4. Easy care: the suit will go through the washing machine often, so it needs to hold up.

A rash guard is a great option at this age, especially for beach days or water parks. It covers the shoulders and back, the areas most exposed to the sun. Browse our girls' swimwear and boys' swimwear starting at size 2.

Ages 6 to 10: Style Enters the Picture

At this age, kids start having real opinions about what they wear. Swimsuit shopping becomes a bit more of a team effort. The print, the color, the cut: they'll want a say in all of it.

What Matters at This Stage

• A cut designed for high-energy activity: swimming, water slides, pool games... the suit has to hold its own.
• Chlorine-resistant fabric: recycled REPREVE polyester holds up well against treated pool water.
• A style that reflects their personality: no more sneaking in the blue-striped suit if your son is obsessed with sharks or your daughter wants tie-dye.

For boys, swim trunks and boardshorts are usually the top pick at this age. For girls, both two-piece sets and one-pieces with fun details like cutouts or ruffles are popular.

Rash Guard or Classic Swimsuit?

A rash guard is still a solid choice, especially for outdoor water activities or full days at the beach. For indoor pools or swimming lessons, a classic suit (a one-piece for girls, boardshorts for boys) is often more practical. Take a look at the full girls' collection and boys' collection to find the right fit.

Ages 10 to 14: Growing Independence

Preteens have strong opinions and are more aware of how they look. At this stage, the most important thing is finding a swimsuit they feel genuinely comfortable and confident in.

Things to Check

• A cut that works for their changing body: kids grow fast at this age. It's worth checking the size guide carefully rather than going by the age on the label.
• Quality materials: a good swimsuit should last a full summer, even with daily swims.
• A design they picked themselves: getting them involved in the choice means they'll actually want to wear it.

Our girls' swimwear collection and boys' swimwear collection offer something for every personality, from understated to bold.

A Note on Fabrics

At Deux par Deux, all our swimwear is made from REPREVE recycled polyester, sourced from recovered plastic bottles. That's not just an environmental choice: it's also a fabric that dries quickly, resists chlorine and UV exposure, and keeps its color wash after wash.

What we avoid: anything that soaks up water and takes forever to dry, or that loses its shape after a few swims. A great swimsuit is a worthwhile investment for the whole season.

Practical Tips Before You Buy

• Check the UPF rating: for kids, UPF 50+ is non-negotiable.
• Size up: children grow fast, and a suit that's slightly big at the start of summer will fit perfectly by the end.
• Think about how it'll be used: indoor pool, beach, water park? The context can help guide the choice.
• Use the size guide: every brand has its own sizing standards, so age labels alone can be misleading.

Finally, keep in mind that even the best swimsuit is no substitute for adult supervision. The Canadian Paediatric Society is clear on this: children should always be supervised near water, regardless of how well they swim.

With the right framework in place, choosing a bathing suit for your child becomes a lot more straightforward, and almost as fun as the swim itself.