UPF 50+ is all you need for kids' swimwear.

Yes. Just look for UPF 50+ on the tag and move on. That rating blocks 98% of UV rays, which is the maximum you’ll get from fabric. Anything lower (UPF 30, etc.) is not worth paying extra for.

Coverage matters more than the number. A long-sleeve rash guard with a high collar protects better than a short-sleeve shirt with UPF 100. Built-in UV protection doesn’t last forever—sunscreen, chlorine, and stretching degrade it. If the suit gets saggy or faded, replace it.

Don’t overthink brand or fabric tech. The $12 Target rash guard works as well as the $40 Patagonia one, assuming both are UPF 50+. Fit is the real decider: if it’s too loose, UV gets through; too tight and they’ll fight you. Buy the size that fits now, not next summer.

Your kid will outgrow it in six months anyway.