Kids' Shoe Size Chart by Age (Baby, Toddler, Big Kid)
Babies grow three shoe sizes in their first year. Toddlers grow 1.5 a year. By age 12, most kids are wearing adult sizes. Here's the full chart by age and foot length, with US/UK/EU/JP conversions.
Kids' shoe sizing is two systems mashed together: a baby/toddler/youth scale that runs 0 to 13.5, and a "big kid" or "youth" scale that runs 1Y to 7Y. The numbers don't carry over — kids 13.5 is followed by 1Y, not 14. And once your child outgrows 7Y, they're in adult sizes.
The single most useful thing: measure foot length and use that as the primary number. Age is a rough guide; foot length is the actual data.
Baby / Infant Shoes (0–24 Months)
| Age | Foot length (in) | Foot length (cm) | US | UK | EU |
|---|---|---|---|---|---|
| 0–3 mo | 3.5" | 8.9 cm | 0 | 0 | 16 |
| 3–6 mo | 3.75" | 9.5 cm | 1 | 0.5 | 16–17 |
| 6–9 mo | 4.0" | 10.2 cm | 2 | 1 | 17–18 |
| 9–12 mo | 4.25" | 10.8 cm | 3 | 2 | 18–19 |
| 12–15 mo | 4.5" | 11.4 cm | 4 | 3 | 19–20 |
| 15–18 mo | 4.75" | 12.1 cm | 5 | 4 | 20–21 |
| 18–24 mo | 5.0" | 12.7 cm | 6 | 5 | 22 |
Pre-walking babies don't strictly need shoes (soft booties or socks are better for foot development). Shoes are useful when crawling outdoors or once they're walking confidently.
Toddler Shoes (Age 2–4)
| Age | Foot length (in) | Foot length (cm) | US | UK | EU |
|---|---|---|---|---|---|
| 2 yr | 5.25" | 13.3 cm | 7 | 6 | 23 |
| 2.5 yr | 5.5" | 14.0 cm | 8 | 7 | 24 |
| 3 yr | 5.75" | 14.6 cm | 9 | 8 | 25 |
| 3.5 yr | 6.0" | 15.2 cm | 10 | 9 | 26–27 |
| 4 yr | 6.25" | 15.9 cm | 11 | 10 | 28 |
| 4.5 yr | 6.5" | 16.5 cm | 12 | 11 | 29–30 |
Little Kid / Big Kid (Age 5–12)
| Age | Foot length (in) | Foot length (cm) | US | UK | EU |
|---|---|---|---|---|---|
| 5 yr | 6.75" | 17.1 cm | 13 | 12 | 31 |
| 5.5 yr | 7.0" | 17.8 cm | 13.5 | 12.5 | 31–32 |
| 6 yr | 7.25" | 18.4 cm | 1Y | 13 | 32–33 |
| 7 yr | 7.5" | 19.1 cm | 2Y | 1 | 33 |
| 8 yr | 7.75" | 19.7 cm | 3Y | 2 | 34 |
| 9 yr | 8.0" | 20.3 cm | 4Y | 3 | 35–36 |
| 10 yr | 8.25" | 21.0 cm | 5Y | 4 | 37 |
| 11 yr | 8.5" | 21.6 cm | 6Y | 5 | 38 |
| 12 yr | 8.75" | 22.2 cm | 7Y | 6 | 39 |
Note the jump: kids size 13.5 is followed by 1Y (not 14). 1Y is barely bigger than 13.5 — the relabel happens at the same foot length range. After 7Y, kids transition to adult sizing (men's 8 ≈ kids' 7Y).
Cross-Reference: Kids to Adult Equivalents
| Kids' US | Adult women's US | Adult men's US |
|---|---|---|
| 3Y | 5 | — |
| 4Y | 6 | — |
| 5Y | 7 | 5 |
| 6Y | 8 | 6 |
| 7Y | 8.5–9 | 7 |
Useful because kids' shoes are typically cheaper than equivalent women's or men's shoes. A women's size 8 sneaker buyer can often save 30–40% by buying the same model in kids' 6Y instead, if available.
How to Measure Kids' Feet
- Use a sheet of paper and a pencil. Have your child stand barefoot on the paper.
- Trace the foot or mark heel and longest toe. For wriggly toddlers, just mark heel and longest toe — don't try to trace.
- Measure heel to longest toe. Some kids' longest toe is the second toe, not the big toe.
- Add 0.25 inch (0.5 cm) for growing room. The shoe should be slightly larger than the bare foot.
- Measure both feet. Use the larger one.
- Measure in the afternoon. Feet are slightly larger after standing/walking.
For more on adult foot measurement (which works the same way), see how to measure your foot length and width.
When to Replace
Common Mistakes
Buying by age alone
Kids of the same age can be 2 shoe sizes apart. Always measure foot length, not calendar age.
Sizing up a full size for growth
A full size up causes the heel to slip and the shoe to feel unstable — actively unsafe for new walkers and athletic activities. Half a size up is fine; full size up is not.
Skipping the width check
Some brands (Stride Rite, See Kai Run, New Balance Kids) offer wide widths. If your child's feet leave deep red marks across the ball, look for wide options.
Buying online without checking brand-specific runs
Adidas Kids run 0.5 size larger than Nike Kids. Crocs run a full size larger than the label. Always check the specific brand's chart.
FAQs
How are kids' shoe sizes determined?
By foot length. Three ranges: infant 0–7, toddler 7–13.5, big kid 1Y–7Y.
When do kids switch to adult shoe sizes?
Around 7Y. Kids 7Y ≈ adult women's 8.5–9 or men's 7.
How often do kids' feet grow?
Babies: 2–3 sizes/year. Toddlers: 1.5/year. Pre-K: 1/year. School age: ~1/year.
Should I buy kids' shoes a size up for growth?
Half a size is fine. A full size up causes the heel to slip.
Do US, UK, EU kids' shoe sizes line up?
Roughly. UK runs 0.5–1 smaller than US. EU and JP use cm direct.
How do I measure a baby's foot?
Lay flat on paper, gently flatten the foot, mark heel and longest toe.
Foot Length Is the Number That Matters
Age estimates are useful for ballpark; foot length is the actual data. A 90-second tracing every 2–3 months saves hundreds of dollars in shoes that almost fit.
For full kids' clothing (not just shoes), see kids' clothing size chart by age and height and how to measure your child for a school uniform.
Selling kids' shoes on Shopify? Sizing returns are highest in this category.
Tailor Size Guide adds foot-length matching to every kids' shoe listing — so parents pick the right US/UK/EU size without guessing.