Short answer
The same number size covers different heights at different brands.
From size 4 to size 12, the gap between the tallest-cut and shortest-cut brand is about 10 cm. At size 14 it is 15 cm.
Each step up the number ladder adds about 7 cm.
4T is not the same as 4: across the brands that publish both, size 4 is a median 2.1 cm taller.
Number sizes in cm: the lookup table
Number sizes are the US-style labels 4, 5, 6, 7, 8, 10, 12 and 14. The table uses the published height ranges of 20 brands, boys and girls kept separate, as of October 2026.
| Size | Brands | Most common bracket | Lowest-cut brand | Highest-cut brand | Gap (cm) |
|---|---|---|---|---|---|
| 4 | 16 | 96.5-106.7 cm (2 of 16) | The Children's Place: 96-104 cm | Amazon Essentials: 107-112 cm | 9.5 |
| 5 | 17 | 104-112 cm (3 of 17) | Nike Kids: 104-110 cm | Amazon Essentials: 114-119 cm | 9.5 |
| 6 | 18 | 112-118 cm (3 of 18) | H&M: 110-116 cm | Amazon Essentials: 122-124 cm | 10.0 |
| 7 | 18 | 121.9-129.5 cm (3 of 18) | Next: 119-125 cm | Polo Ralph Lauren Kids: boys 124-134; girls 130-134 cm | 8.5 |
| 8 | 18 | 131-136 cm (3 of 18) | Cotton On: 125-130 cm | Polo Ralph Lauren Kids: 136-138 cm | 9.5 |
| 10 | 18 | 136-142 cm (2 of 18) | Cotton On: 130-140 cm | Lands' End: boys 136-143; girls 146-152 cm | 9.2 |
| 12 | 18 | 142-147 cm (2 of 18) | H&M: 140-146 cm | Hanna Andersson: 147.3-157.5 cm | 9.4 |
| 14 | 15 | 147-151 cm (2 of 15) | Carter's: 147-151 cm | Next: 161-167 cm | 15.0 |
Sizes 3 (7 brands) and 6X (6 brands) are left out: too few brands publish them, so the figures are indicative only.
Size 6 across 18 brands
At size 6 the shortest-cut range is H&M "116 (6)" at 110-116 cm. The tallest is Amazon Essentials at about 122-127 cm, allowing for its whole-inch notation; the table shows the stored figure. The median bracket midpoint is 117.6 cm, and the most common bracket, 112-118 cm, is shared by only 3 of 18 brands.
| Brand | Label | Chart | Height range |
|---|---|---|---|
| H&M | 116 (6) | boys and girls | 110-116 cm |
| Nike Kids | 6 | boys and girls | 110-116 cm |
| Gymboree | 6 | boys and girls | 112-118 cm |
| Primary | 6 | boys and girls | 112-119 cm |
| The Children's Place | 6 | boys and girls | 112-118 cm |
| Under Armour | 6 | boys and girls | 112-118 cm |
| Next | 6 | boys and girls | 113-119 cm |
| Carter's | 6 | boys and girls | 114-122 cm |
| OshKosh B'Gosh | 6R | boys | 114-122 cm |
| Cat & Jack | 6 | girls | 114.3-119.4 cm |
| Disney | 6 | boys and girls | 114.3-121.9 cm |
| Janie and Jack | 6 | boys and girls | 114.3-121.9 cm |
| Jumping Beans | 6 | boys and girls | 114.3-121.9 cm |
| Wonder Nation | 6 | boys | 114.3-120.7 cm |
| Wonder Nation | 6 | girls | 114.3-118.1 cm |
| Cotton On | 6 | boys and girls | 115-120 cm |
| Lands' End | 6 | boys | 115-119 cm |
| Lands' End | 6 | girls | 115-122 cm |
| Polo Ralph Lauren Kids | 6 | boys and girls | 117-123 cm |
| Cat & Jack | 6 | boys | 119.4-125.7 cm |
| Amazon Essentials | 6 | boys and girls | 122-124 cm |
Each step up the ladder adds about 7 cm: the median step is 7.3 cm from size 4 to 5, 7.1 cm from 5 to 6, 7.4 cm from 6 to 7 and 7.1 cm from 7 to 8. From size 8 the numbers skip (8, 10, 12, 14), so a step of about 7 cm covers two years, or about 3.5 cm per year.
Older number sizes grow slowly: brand ladders add about 3 to 4 cm a year from size 10 to 14, against about 5 to 7 cm for the typical child (CDC).
4T is not 4
Size 4 is a median 2.1 cm taller than 4T across the 8 brands that publish both. For 5T against 5 the figure is 2.5 cm across 5 brands. The difference ranges from 0 cm (Jumping Beans, Nike Kids, Under Armour, Wonder Nation) to 8 cm (Amazon Essentials).
| Brand | Toddler size | Number size | Size number taller by (midpoint) |
|---|---|---|---|
| Amazon Essentials | 4T: 99-104 cm | 4: 107-112 cm | 8 cm |
| Carter's | 4T: 99-105 cm | 4: 102-108 cm | 3 cm |
| Cat & Jack | 4T: 99-109.2 cm | 4: 105.4-110.5 cm | 3.9 cm |
| Jumping Beans | 4T: 100.3-106.7 cm | 4: 100.3-106.7 cm | 0 cm |
| Nike Kids | 4T: 98-104 cm | 4: 98-104 cm | 0 cm |
| OshKosh B'Gosh | 4T: 99-105 cm | 4: 102-108 cm | 3 cm |
| Under Armour | 4 / 4T: 97-104 cm | 4: 97-104 cm | 0 cm |
| Wonder Nation | 4T: 96.5-105.4 cm | 4: 99.1-105.4 cm | 1.3 cm |
| Carter's | 5T: 105-112 cm | 5: 108-114 cm | 2.5 cm |
| Cat & Jack | 5T: 109.2-111.7 cm | 5: 111.75-116.85 cm | 3.8 cm |
| Jumping Beans | 5T: 106.7-114.3 cm | 5: 106.7-114.3 cm | 0 cm |
| OshKosh B'Gosh | 5T: 105-112 cm | 5: 108-114 cm | 2.5 cm |
| Wonder Nation | 5T: 106.7-113 cm | 5: 106.7-113 cm | 0 cm |
No brand in the data publishes both 2T and 2, or 3T and 3.
Number size versus age label
Number sizes at 6 and 8 are cut for taller children than the age label with the same number. By 12 and 14 they are cut for shorter children.
| Size N | Number size N | "N years" age label | Typical child at N years (CDC) |
|---|---|---|---|
| 4 | 103.2 (16 brands) | 101.5 (11 brands) | 101.5 |
| 5 | 110.5 (17 brands) | 107.5 (11 brands) | 108.3 |
| 6 | 117.6 (18 brands) | 113.5 (11 brands) | 115.1 |
| 7 | 125 (18 brands) | 119.5 (9 brands) | 121.6 |
| 8 | 132.2 (18 brands) | 125.2 (12 brands) | 127.7 |
| 10 | 139 (18 brands) | 137 (11 brands) | 138.3 |
| 12 | 145.8 (18 brands) | 149 (11 brands) | 150.1 |
| 14 | 153.4 (15 brands) | 161 (9 brands) | 162.1 |
In practice, number size 8 (most often 131-136 cm) is closest to the UK and European "8-9 years" label (128-134 cm). Number size 14 (147-151 cm) is closest to "12 years" (146-152 cm), well below "14 years" (158-164 cm).
This comparison treats number size N as an age of N years. The cm comparisons elsewhere on this page do not depend on that assumption.
What H&M "116 (6)" means
H&M prints a height in cm with a number size in brackets. In "116 (6)", the 116 is the top of its height range: H&M "116 (6)" covers 110-116 cm, the shortest-cut size 6 of the 18 brands compared.
Boys and girls
26 of 153 brand-size pairs differ by more than 2 cm between the boys and girls charts. Lands' End girls sizes are 8-10 cm taller at sizes 10-12. Cat & Jack boys sizes look shifted one size against Cat & Jack girls: boys 6 is 119.4-125.7 cm, girls 6 is 114.3-119.4 cm.
What to do
Measure your child's height, without shoes, and compare it with the brand's own height range for the size. Do not assume a size 6 at one brand is a size 6 at another, and do not buy by the number alone.
The size finder matches a height to each brand's chart. For the wider picture, see the kids clothing size chart guide.
Questions
Is size 6 the same height at every brand?
No. Across 18 brands, size 6 is published from 110-116 cm (H&M "116 (6)") to 122-124 cm (Amazon Essentials). The most common range, 112-118 cm, is shared by only 3 of 18 brands. Published charts as of October 2026.
Is 4T the same as size 4?
No. Across the 8 brands that publish both, size 4 is a median 2.1 cm taller than 4T. The difference ranges from 0 cm to 8 cm. No brand in the data publishes both 2T and 2, or 3T and 3.
Which age label is closest to number size 8?
Number size 8 is most often published as 131-136 cm. That is closest to the UK and European "8-9 years" label, which is usually 128-134 cm.
Methods and sources
Published brand size charts only: 20 brands, sizes 4 to 14, 327 chart rows, boys and girls kept separate. Brands that publish in inches are converted at 2.54 cm per inch.
Note: some brands round their ranges to whole inches, which leaves small gaps between sizes in the chart. Amazon Essentials' chart lists overlapping ranges for sizes 7 and 8. Some brands publish two ladders in one chart (Carter's, Next, Primary); these are read as published.
Height only. This is not a fit study: chest, waist, hips, rise, stretch and cut are not compared. Plus, husky, slim and extended fits are excluded. Brands change charts; check the brand's own chart before buying.
Data as of October 2026. Full method: How we compare kids' size charts.
Related
Source: CDC. Developed by CDC/NCHS. CDC 2000 growth charts, stature-for-age and length-for-age. Available on the CDC website at no charge. Outgrow's use of CDC data does not imply CDC endorsement of Outgrow or its products.