Children’s shoes are labelled with a mix of systems. A pair marked 10C in the United States is 27 in Europe, 9.5 in the UK and 16 on a Japanese centimetre scale. This converter takes a size in any of four systems and gives the other three, together with the length of foot that the size is made for, using Nike’s kids’ footwear chart.
How to use the kids shoe size converter
- Select the system your size is in.
- Type the size, such as 10C or 2.5Y for US, a number for the others.
- Read the equivalents and the foot length for the size.
- Check the maker’s own size guide before you buy.
Kids shoe size conversion formulas
foot length (in) ≈ (US kids size number + 9¾) ÷ 3 for the whole range (Wikipedia children’s formula)
EU ≈ 1.5 × last length (cm); cm × 0.3937 = in
The conversions are the rows of Nike’s kids’ footwear chart (retrieved 2026-10-15). Wikipedia’s Shoe size page gives the standard formula for children’s sizes, size ≈ 3 × foot length (inches) − 9¾, which agrees with the chart for the small sizes. Foot lengths are in sixteenths of an inch on the chart and converted to centimetres by multiplying by 2.54.
| US kids size | UK | EU | Nike cm / JP | Foot length (in) | Foot length (cm) |
|---|---|---|---|---|---|
| 1C | 0.5 | 16 | 7 | 3 9/16 | 9.0 |
| 2C | 1.5 | 17 | 8 | 3 15/16 | 10.0 |
| 3C | 2.5 | 18.5 | 9 | 4 1/4 | 10.8 |
| 4C | 3.5 | 19.5 | 10 | 4 9/16 | 11.6 |
| 5C | 4.5 | 21 | 11 | 4 15/16 | 12.5 |
| 6C | 5.5 | 22 | 12 | 5 1/4 | 13.3 |
| 7C | 6.5 | 23.5 | 13 | 5 9/16 | 14.1 |
| 8C | 7.5 | 25 | 14 | 5 15/16 | 15.1 |
| 9C | 8.5 | 26 | 15 | 6 1/4 | 15.9 |
| 10C | 9.5 | 27 | 16 | 6 9/16 | 16.7 |
| 10.5C | 10 | 27.5 | 16.5 | 6 3/4 | 17.1 |
| 11C | 10.5 | 28 | 17 | 6 15/16 | 17.6 |
| 11.5C | 11 | 28.5 | 17.5 | 7 1/16 | 17.9 |
| 12C | 11.5 | 29.5 | 18 | 7 1/4 | 18.4 |
| 12.5C | 12 | 30 | 18.5 | 7 7/16 | 18.9 |
| 13C | 12.5 | 31 | 19 | 7 9/16 | 19.2 |
| 13.5C | 13 | 31.5 | 19.5 | 7 3/4 | 19.7 |
| 1Y | 13.5 | 32 | 20 | 7 15/16 | 20.2 |
| 1.5Y | 1 | 33 | 20.5 | 8 1/16 | 20.5 |
| 2Y | 1.5 | 33.5 | 21 | 8 1/4 | 21.0 |
| 2.5Y | 2 | 34 | 21.5 | 8 7/16 | 21.4 |
| 3Y | 2.5 | 35 | 22 | 8 9/16 | 21.7 |
| 3.5Y | 3 | 35.5 | 22.5 | 8 3/4 | 22.2 |
| 4Y | 3.5 | 36 | 23 | 8 13/16 | 22.4 |
| 4.5Y | 4 | 36.5 | 23.5 | 8 15/16 | 22.7 |
| 5Y | 4.5 | 37.5 | 23.5 | 9 1/8 | 23.2 |
| 5.5Y | 5 | 38 | 24 | 9 1/4 | 23.5 |
| 6Y | 5.5 | 38.5 | 24 | 9 3/8 | 23.8 |
| 6.5Y | 6 | 39 | 24.5 | 9 9/16 | 24.3 |
| 7Y | — | 40 | 25 | 9 11/16 | 24.6 |
Worked example
A US size 10C.
- UK 9.5, EU 27, cm / Japan 16.
- Foot length the size is made for: 16.7 cm (6 9/16 in).
- Check with the formula: 3 × 6.5625 − 9.75 = 9.94, so size 10.
Notes
- Allow growing room: a thumb’s width at the toe is normal for children.
- Brands vary: half a size between makers is common.
- Repeated numbers: Nike prints UK 6 for both 6.5Y and 7Y, which looks like a repeat.
- Adults: from about 7Y the adult charts take over; use the Shoe Size Converter (US/UK/EU/JP).
To find a size from your child’s foot use the Kids Shoe Size Calculator; for babies see the Toddler Shoe Size Calculator. This page is general information.
Sources
Every figure above comes from these pages, read directly on the dates shown. Brand names are used only to identify published charts.
- Nike — kids’ shoes size chart (US, UK, EU, cm/JP, foot length) — checked 2026-10-15
- Wikipedia — Shoe size (children’s size formula) — checked 2026-10-15
Frequently asked questions
How do I convert a US kids shoe size to EU?
Use the chart: US 10C is EU 27, US 1Y is EU 32 and US 5Y is EU 37.5. There is no simple formula, because European sizes are in 2/3 centimetre steps and US sizes in about 0.85 cm steps.
What do C and Y mean?
C is for children’s sizes (1C to 13.5C) and Y for youth sizes (1Y to 7Y). After 13.5C the next size is 1Y, so a 13.5C is followed by a 1Y.
Why does the UK size 1.5 appear twice?
UK numbers restart after 13.5, so UK 1.5 is the same number as 1.5 in the older range; the converter returns the first match in the youth range, 2Y. Check the other size system when in doubt.
Is the cm size the foot length?
No: it is the shoe box size. Nike notes that the cm on a label is different from foot length. The converter shows the foot length the size is made for in a separate result.
How do I find my child’s size from the foot?
Measure the longer foot and use the Kids Shoe Size Calculator. For babies and toddlers see the Toddler Shoe Size Calculator.