US kids clothing sizes run 2T, 3T, and 4T, then the numbers 4, 5, 6, 6X, 7, 8, 10, 12, 14, and 16 (often labeled XS to XL). The number starts near your child's age but is built around height and weight, so buy by measurement, because the same label is not the same size across brands.
Shopping a European label around US 10-12? See what size 140 means.
Key takeaways
- Kids sizes go 2T–4T, then 4, 5, 6, 6X, 7, 8, 10, 12, 14, 16; XS–XL letters map to different numbers by brand.
- The size number starts near the child's age but maps to height and weight, so measure before you buy.
- A youth medium is size 8 at Lands' End and Old Navy but sizes 10–12 at Nike and Under Armour — check the brand's own chart.
- European sizes are simply the child's height in centimeters (a US 5 is about EU 110).
- Labels drift by brand — in our 2026 Size Index the same label was not the same size, so trust the tape measure.
How do US kids clothing sizes work?
US kids sizes start where toddler sizes end. After 2T, 3T, and 4T, the sizes switch to single numbers — 4, 5, 6, 6X, 7, 8, 10, 12, 14, 16 — and some brands add XS to XL letters, which map to different numbers by brand. The number begins near your child's age, but it is drawn from standard height and weight ranges, so fit follows the body, not the birthday. A 6X sits between a regular 6 and a 7, giving a little extra length and width for a child who has outgrown a 6 but is not ready for a 7. Around size 7, many brands split into separate boys' and girls' departments. For the step up from toddler clothes, see what size a 2-year-old wears.
What is the full kids and youth size chart by age and height?
Here is the full picture in one place. Ranges are approximate and overlap on purpose — pick the size whose height and weight range best matches your child, and size up when they fall between two. XS to XL letters differ by brand; see the youth letter table below.
| US kids size | Approx age | Height | Weight | EU (cm) |
|---|---|---|---|---|
| 2T | ~2 yr | 33–35 in (84–89 cm) | 28–30 lb | 86–92 |
| 3T | ~3 yr | 36–38.5 in (91–98 cm) | 31–34 lb | 92–98 |
| 4T / 4 | 4–5 yr | 39–42 in (99–107 cm) | 35–40 lb | 104–110 |
| 5 | 5–6 yr | 42–45 in (107–114 cm) | 40–46 lb | 110 |
| 6 | 6–7 yr | 45–47 in (114–120 cm) | 46–52 lb | 116–120 |
| 6X / 7 | 7 yr | 47–50 in (120–127 cm) | 52–58 lb | 122 |
| 8 | 8 yr | 50–53 in (127–135 cm) | 58–66 lb | 128–134 |
| 10 | 9–10 yr | 53–57 in (135–145 cm) | 66–76 lb | 140 |
| 12 | 11–12 yr | 57–61 in (145–155 cm) | 76–90 lb | 146–152 |
| 14 | 12–13 yr | 61–63 in (155–160 cm) | 90–105 lb | 158–164 |
| 16 | 13–14 yr | 63–65 in (160–165 cm) | 105–120 lb | 170 |
The size 16 age is the age label (13–14 yrs) Lands' End's chart prints for US 16.
Sizes are approximate general fit guidance, not medical or growth advice. Children grow at their own pace, so if you have questions about your child's growth or development, ask your pediatrician. See our medical disclaimer.
What size is a youth XS?
Youth XS (YXS) is sizes 4–5 at Lands' End and Target (Cat & Jack), size 5 at Old Navy, sizes 6–7 at Nike and size 7 at Under Armour. Boys-chart heights: 40–45 inches at Lands' End, 48–50 at Nike. Check the brand's chart.
What size is a youth small?
A youth small (YS) is sizes 6–7 at Lands' End, Old Navy and Target (Cat & Jack boys), sizes 6–8 at Gildan, size 8 at Under Armour and sizes 8–9 at Nike. Boys-chart heights: 46–49 inches at Lands' End, 50–54 at Nike. Check the brand's chart.
What size is a youth medium?
A youth medium (YM) is size 8 at Lands' End, Old Navy and Target (Cat & Jack boys clothing), and sizes 10–12 at Nike, Under Armour and Gildan. Boys-chart heights: 50–53 inches at Lands' End, 54–58 at Nike. Check the brand's chart.
What size is a youth large?
A youth large (YL) is sizes 10–12 at Lands' End, Old Navy and Target (Cat & Jack boys clothing), and sizes 14–16 at Nike, Under Armour and Gildan. Boys-chart heights: 54–59 inches at Lands' End, 58–62 at Nike. Check the brand's chart.
What size is a youth XL?
A youth XL (YXL) is sizes 14–16 at Lands' End and Old Navy, which also print an XXL for 18–20, and sizes 18–20 at Nike, Gildan and Under Armour boys. Boys-chart heights: 60–65 inches at Lands' End, 62–67 at Nike. Check the brand's chart.
What is a youth shirt size chart (XS to XL)?
There is no single youth shirt size chart: brands print different numbers for the same letter. Of the 7 brands with letter sizes whose boys charts we read on October 1, 2026, 3 (Lands' End, Old Navy, Target's Cat & Jack) print M as size 8 and L as 10–12; 3 (Nike, Under Armour, Gildan) print M as 10–12, L as 14–16 and XL as 18–20; Gap prints letters and heights but no US numbers.
| Brand (chart) | Youth XS | Youth S | Youth M | Youth L | Youth XL |
|---|---|---|---|---|---|
| Print M as size 8 | |||||
| Lands' End (boys regular) | sizes 4–5 40–45 in |
sizes 6–7 46–49 in |
size 8 50–53 in |
sizes 10–12 54–59 in |
sizes 14–16 60–65 in |
| Old Navy (boys) | size 5 42–45 in |
sizes 6–7 45–51 in |
size 8 51–54 in |
sizes 10–12 54–60 in |
sizes 14–16 60–65 in |
| Target Cat & Jack (boys clothing) | sizes 4–5 43–47 in |
sizes 6–7 47–52.5 in |
size 8 52.5–54 in |
sizes 10–12 54–59.5 in |
size 14 59.5–62 in |
| Print M as sizes 10–12 | |||||
| Nike (boys) | sizes 6–7 48–50 in |
sizes 8–9 50–54 in |
sizes 10–12 54–58 in |
sizes 14–16 58–62 in |
sizes 18–20 62–67 in |
| Under Armour (boys) | size 7 47–50½ in |
size 8 50½–53 in |
sizes 10–12 53–59 in |
sizes 14–16 59–65 in |
sizes 18–20 65–70 in |
| Gildan (boys tees) | — | sizes 6–8 | sizes 10–12 | sizes 14–16 | sizes 18–20 |
| Letters only, no US numbers | |||||
| Gap Kids (boys regular) | 39–45 in | 45–51 in | 51–54 in | 54–57 in | 57–60 in |
Cells show what each brand's boys chart prints; a height across two sizes spans both printed rows. Girls charts can differ: Target's prints M as 7–8, Under Armour's prints XL as 18. Target also has a second Cat & Jack boys chart that prints M as 8–10 and L as 12–14; the first chart's conversion table lists that scale as “Previous Target Size”. Gildan's chart prints no height.
Boys size chart vs girls size chart: what is the difference?
Through the toddler and little-kid years, boys' and girls' numeric sizes use the same numbers and nearly the same height and weight ranges. They diverge around size 7: Target's girls chart adds a 6X, and brands print different body measurements for boys and girls at the same number. At size 10, Lands' End prints a 27½-inch chest and 25½-inch waist for boys, and 28½ and 25 inches for girls. The age-to-height guide above is a starting point for both, so check the brand's boys or girls chart.
How do US kids sizes convert to EU sizes?
European sizes are the simplest system of all: the number is the child's height in centimeters. A US 5 is about EU 110, a US 8 is about EU 128, and a US 14 is about EU 158–164. Measure height in centimeters and match the nearest EU number. Our EU size conversion guide (50 to 140) lists every step from newborn to teen.
Why does the same size fit differently across brands?
Because the label is not a standard. In our 2026 Size Index we compared 30 brands sold in the US and found the same label was not the same garment: the same “3-6M” label tops out anywhere from 14.5 lb to 20 lb depending on the brand, and “18-24M” ranged from about 26 to 32 lb. The same pattern shows up across kids and youth sizes, so two size-8 shirts from different brands can fit a child quite differently. The honest takeaway is to buy by measurement, not by the number on the tag.
How do I measure my child for the right size?
Stand your child against a wall to read height, then use a soft tape for the chest (around the fullest part), the waist (at the natural waistline), and the hip. Compare those numbers to the chart's ranges rather than to the age column, since age is only a starting point. When your child lands between two sizes, size up — kids grow into clothes faster than they grow out of them. Our free Size Finder turns a few measurements into a recommended size in seconds.
Sources: Babbez Baby Clothing Size Index 2026 (30 brands sold in the US); Babbez EU size conversion guide (50–140); the brand size charts linked in the youth letter table above (Lands' End, Old Navy, Gap, Target, Nike, Under Armour, Gildan); brands change them, so check the brand's own chart. The main chart's ranges are approximate, not one brand's chart. ASTM sells body-measurement tables for girls and boys (D6192/D6192M, D6458/D6458M); they were not used for the numbers on this page. This chart is general fit guidance and not medical advice; see our medical disclaimer.