Youth Shoe Size Chart by Brand: Nike vs adidas vs New Balance

A youth size 3.5 fits a foot between 8½ and 8¾ inches long depending on the brand — a quarter-inch spread, or about three-quarters of a shoe size. adidas runs shortest at that label, Nike longest, New Balance in between. By youth 7 the three brands land within a sixteenth of an inch of each other, so the difference that matters is at the small end of the range.

Below are the three brands’ own published foot lengths side by side, so you can match the measurement instead of trusting the number on the box.

Youth shoe size chart by brand

These are foot lengths, not shoe lengths — the length of the child’s foot that each size is built to fit. Measure the foot, find the closest number in the column for the brand you are buying, and take that size.

adidas publishes whole and half sizes on a different grid from the other two, which is why some rows are blank — it lists 3, 3.5, 4, 5, 6, 7 but not 4.5, 5.5 or 6.5 in its youth conversion chart.

Which brand runs small?

adidas. At youth 3.5 an adidas shoe is built for an 8½-inch foot while a Nike of the same label is built for 8¾ inches. A child whose foot measures 8¾ inches takes a Nike 3.5Y, a New Balance 4, and an adidas 4 or larger. The gap closes as sizes go up, and above youth 6 the three are effectively interchangeable.

Width is the part no chart above shows. New Balance publishes multiple widths in many kids’ models, which is the practical reason to look there first for a broad or narrow foot — a shoe that is the right length in the wrong width still does not fit.

What is the biggest youth shoe size?

Youth 7 is the largest, on all three brands. It is built for a foot of roughly 9¾ inches, and it is where the youth range stops and adult sizing takes over. New Balance states plainly that grade school sizes continue on the men’s scale, so a youth 7 sits close to a men’s 7.

This matters more than it sounds, because the youth range is usually cheaper than the adult equivalent of the same shoe. A child whose foot is still under 9¾ inches can stay in youth sizes — and once the foot passes that, the next purchase moves to adult pricing whether you are ready or not. If your child is near the top of the range, our kids shoe size chart has the youth-to-women’s and youth-to-men’s conversions.

Even one brand publishes two different charts

Nike’s own site lists its big kids sizes in both inches and centimetres. Its retailers list the same Nike sizes with centimetre figures that are consistently half a centimetre different:

The EU numbers are identical across both — it is only the centimetre column that moves. There is a second oddity inside Nike’s own chart: 5.5Y and 6Y are both listed at 24 cm, which cannot be right for two different sizes, and the inch column separates them (9¼ against 9⅜). We are leaving both of these visible rather than picking the version that looks tidiest, because the practical conclusion is the same either way: use the inch column and your own measurement, not the centimetre conversion someone else typed.

How to measure a foot properly

Measure late in the day, standing, with the sock they will actually wear. Feet swell over the course of a day, and a foot measured lying down is shorter than the same foot bearing weight.

1. Tape a sheet of paper to a hard floor, against a wall.
2. Have your child stand on it with the heel touching the wall, weight on both feet.
3. Mark the paper at the tip of the longest toe — which is not always the big toe.
4. Measure from the wall edge to the mark. Do this for both feet and use the longer one.

When to size up, and by how much

Add about half an inch of growing room beyond the measured length before matching it to the chart. That is roughly a thumb’s width at the toe when the shoe is on, and it is the standard allowance — not extra generosity. Going beyond that turns into a trip hazard rather than a longer-lasting shoe.

Three things the chart cannot tell you

• How fast the foot is moving. Children’s feet grow in bursts, and a shoe bought with half an inch of room can be tight in three months during one.
• Whether the model is cut narrow. Two shoes from the same brand in the same size can differ in width by model — a soccer boot is cut tighter than a running shoe on purpose.
• Whether the child will say anything. Kids adapt to shoes that are too small without complaining. Measure on a schedule rather than waiting to be told.

Sources and verification

Every figure on this page comes from a published size chart, and the verification level differs by brand — we are stating which is which rather than presenting them as equally solid:

• Nike — foot lengths in inches taken from Nike’s own kids’ footwear size chart on nike.com. Cross-checked against a retailer’s published Nike grade-school chart, which agrees on every EU size and differs on the centimetre column; that disagreement is shown above rather than resolved.
• adidas — two independent size-chart publishers give identical foot lengths for the youth range (7.7″ at US 1 through 9.7″ at US 7). adidas’s own US help pages did not return a readable chart at the time of checking.
• New Balance — the full grade-school chart comes from a single size-chart publisher. Two of its rows are corroborated by New Balance’s own published figures (a grade-school 5.5 fitting a 9¼-inch foot and a 7 fitting 9¾), so the shape of the chart is confirmed even though the whole table rests on one source. Treat the New Balance column as the least-verified of the three.

We are not a testing lab; these are the brands’ published numbers, compared. Brands revise charts without notice, so check the chart on the product page for the specific model before ordering.

Last verified: 28 September 2026. Spotted a number that has changed? Tell us — corrections get the chart re-checked and re-dated.

More charts: every kids size chart in one place. For shirts, the same brand-by-brand problem is covered in our youth size chart by brand.