What is a 3T?How 3T sizing compares across 45 kids' brands

A 3T is designed with 3-year-olds in mind, but age is only a rough guide. Because a 3T is built around height and build, plenty of children wear a 3T a year earlier or later than the label suggests. Checking your child's height against a specific brand's 3T is far more reliable than going by age alone.

Most brands cut a 3T for a toddler about 36–39" tall, but across brands it runs 34–39½" — that full span is the honest answer. Height is what determines fit, so check your child's height against the specific brand's 3T rather than going by the age on the label.

Neither, reliably — a 3T is not standardized. Across these 45 brands it covers heights from 34 to 39½", a spread of about 5½ inches. It runs longer at Polo Ralph Lauren Kids, Kohl's Jumping Beans, and Reebok Kids and shorter at Garanimals, Macy's Epic Threads, and Macy's First Impressions, with most brands in between, 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 3T height range, which is why a 3T cannot be carried from one brand to the next: the size that fits in one brand can be short or roomy in another even though the label is identical.

Mostly the cut, not the height. A 3T is cut fuller through the middle for a toddler still in diapers; a straight 3 is leaner, for a child out of them. Only a few brands publish a 3 at all, so most of the time the real choice is 2T–3T–4T by height. Compare your child’s height to the specific brand’s chart rather than going by the label.

After a 3T, most brands move to a 4T. Sizing can shift noticeably at that step, so it's worth checking the next size's height range rather than assuming it picks up exactly where the 3T left off.

When your child's height is near the top of a brand's published 3T range, check that brand's a 4T before buying — the next size's range doesn't always pick up where 3T ends. We can't predict how long a garment lasts, so we point you to the boundary, not a guess.

Among the brands here, Kohl's Jumping Beans cuts the longest 3T, fitting up to about 39½ inches of height. That is about published height only — it says nothing about how long the garment itself lasts.