What is a size 12?How girls' and boys' size 12 compare across 34 kids' brands

A size 12 is designed with 12-year-olds in mind, but age is only a rough guide. Because it is built around height and build, plenty of children wear a size 12 a year earlier or later than the label suggests. Checking your child's height against a specific brand's chart is far more reliable than going by age alone.

Most brands cut a girls' size 12 for about 56–59" and a boys' size 12 for about 57–59", but across brands the label covers 55–61" — that full span is the honest answer. Check your child's height against the brand you are buying.

Not always. Many brands publish one unisex size 12 that covers both, but 18 of the 34 brands here chart girls and boys separately — and where they do, the two can differ by an inch or more at the same number. The table above shows both, so you can compare the one that matches your child.

Neither, reliably — a size 12 is not standardized. Across these 34 brands it covers heights from 55 to 61", a spread of about 6 inches, so "big" or "small" only means anything next to a named brand.

No, and there is no industry standard that would make it so. Each brand sets its own size 12 height range, which is why the number cannot be carried from one brand to the next: the size that fits in one can be short or roomy in another under an identical label.

Some brands do — the same numbered size, taken in or let out through the waist and seat rather than cut to a different height. Little & Youth tracks those separately: see the slim, plus and husky guides for which brands publish them and how they compare.

After a size 12, most brands move to a size 14. Sizing can shift noticeably at that step, so it is worth checking the next size's height range rather than assuming it picks up exactly where size 12 left off.

When your child's height is near the top of a brand's published size 12 range, check that brand's a size 14 before buying — the next size's range doesn't always pick up where size 12 ends. We can't predict how long a garment lasts, so we point you to the boundary, not a guess.

Among the brands here, Converse Kids cuts the longest size 12, fitting up to about 61 inches of height. That is about published height only — it says nothing about how long the garment itself lasts.