Sizing was slightly inconsistent, as the boys underwear seems to run on the smaller side, while the girls style skews a little large, so keep that in mind while shopping. And note that, although we didn’t experience any issues with the elastic waistbands digging in, we were disappointed by the long tag inside the underwear. Most kids, particularly those with sensitive skin and sensory issues, will be more comfortable if you snip those off before your kiddos wear them.
Best Range of Sizes: Primary Kids’ Underwear
A lot of kids’ underwear is designed for toddlers or bigger kids, but what we like about Primary is that you can find sizes 2-3 through 14 in all of the brand’s styles. This way, if you find something your child likes, they can ride the wave through their teen years—no need for continual experimentation.
We found the underwear to be supremely comfortable. A finicky five-year-old who tested the boxer shorts never once complained about bunching or tightness. We attribute it to the 95% cotton and 5% elastane construction that includes flat seams and a softer, no-roll waistband.
The girls’ style we tested, the classic bikini, was also met with rave reviews from kids and parents alike. “It runs a tad bit big, but I love that it offers a little more coverage than your average bikini, so even the most active won’t get constant wedgies,” one parent said. “I like the prints and colors as opposed to characters, too. These can better grow with my girl.”
Best Stretchy: Reebok Underwear
For just about the same price as our top value pick, Reebok makes underwear that’s so stretchy and comfortable it’s basically performance wear. The girls’ hipster underwear, which is made of 100% nylon for optimal stretch, is one of the brand’s top-rated picks. They’re seamless and tag-free—ideal for anyone with sensitive skin. We also like that the longer leg is intended to help prevent chafing. Overall, this comfortable underwear is a great pick for all-day wear or something specific like athletic practices.
The boys style that made our list is arguably even more popular, largely because of its breathability. The pair is made of 92% polyester and 8% spandex and is one of the lightest styles I’ve held in my hands. Still, it offers enough compression to keep your little guy comfortable even at his most active. My six-year-old son has a set of these and a 100% cotton pair that fits more loosely, but reaches for these every time because they’re “less scratchy.” I love that they seem to hold up very well in the wash, too. We’ve had them for well over a year, and no holes or stretching yet.
Best for Older Kids: Old Navy Underwear
When shopping for kids and baby clothes, you probably already know Old Navy is a great one-stop-shop for affordable basics—and that includes underwear. Both styles we cherry-picked based on parent reviews are made of a soft-washed cotton blend jersey that moves with the body. The elasticized waist on both pairs ensures there’s no rolling, but wearers don’t have any complaints about it digging in, either.
