👟 Kids Shoe Size by Age Calculator
Estimate your child's US, UK and EU shoe size from their age and foot length — and find out when the next size up is likely.
📏 Kids Shoe Size Chart by Age (US / UK / EU)
The chart below shows the shoe size worn by a typical child at each age, based on average foot length. These are averages, not rules: a healthy child can sit a full size above or below the line for their age and still be entirely normal. Genetics, not nutrition, drives most of the variation — tall parents tend to have children with longer feet at the same age.
| Age | Foot Length (cm) | US Kids Size | UK Size | EU Size | Typical Growth |
|---|---|---|---|---|---|
| 1 years | 12.0 cm | US 4.5 | UK 4.0 | EU 20 | ~3 months |
| 2 years | 13.5 cm | US 6.0 | UK 5.5 | EU 22 | ~3 months |
| 3 years | 15.0 cm | US 8.0 | UK 7.5 | EU 25 | ~5 months |
| 4 years | 16.0 cm | US 9.0 | UK 8.5 | EU 26 | ~5 months |
| 5 years | 17.0 cm | US 10.5 | UK 10.0 | EU 28 | ~5 months |
| 6 years | 18.0 cm | US 11.5 | UK 11.0 | EU 29 | ~7 months |
| 7 years | 19.0 cm | US 12.5 | UK 12.0 | EU 31 | ~7 months |
| 8 years | 20.0 cm | US 14.0 | UK 13.0 | EU 32 | ~7 months |
| 9 years | 21.0 cm | US 15.0 | UK 14.0 | EU 34 | ~7 months |
| 10 years | 22.0 cm | US 16.0 | UK 15.0 | EU 35 | ~9 months |
| 11 years | 23.0 cm | US 17.5 | UK 16.5 | EU 37 | ~9 months |
| 12 years | 23.8 cm | US 18.5 | UK 17.5 | EU 38 | ~9 months |
| 13 years | 24.5 cm | US 19.0 | UK 18.0 | EU 39 | ~9 months |
Girls' feet usually mature earlier than boys'. On average a girl's foot reaches roughly 90% of its adult length by age 12, while a boy's reaches the same point around age 14. That means a 10-year-old girl and a 10-year-old boy often wear different sizes even when they are the same height — which is why this calculator asks for sex as well as age.
📖 How to Measure a Child's Foot at Home
Measuring at home takes two minutes and is far more accurate than guessing from age or from the size printed on the shoes your child is currently wearing. Those labels are unreliable: a worn-in shoe can be half a size larger than its label, and children routinely stay in a shoe weeks after they have outgrown it because the toe box still feels comfortable.
Measure in the afternoon or early evening. Feet swell through the day and are at their smallest first thing in the morning, so a shoe that fits at 8am may pinch by 4pm. Always measure both feet — it is normal for one foot to be up to half a size larger, and you should fit the larger foot.
Have your child stand up, not sit. Standing puts full weight on the foot and spreads it to its true length; a measurement taken sitting down can under-read by several millimetres, which is enough to land you in the wrong size.
- Tape a sheet of A4 paper flat against a wall or skirting board.
- Ask your child to stand with the heel lightly touching the wall.
- Mark the tip of the longest toe — that is often the second toe, not the big toe.
- Repeat for the other foot and take the larger measurement in centimetres.
- Add 0.5–1 cm of growing room for toddlers and about 1 cm for school-age children.
Then enter the raw foot length in the calculator above and it will convert straight to US, UK and EU sizing. For a toddler under three, re-measure every two to three months; children between three and six generally need a check every four months, and from seven upwards twice a year is usually enough.
💡 Why It Matters
🦶 Ill-fitting shoes deform feet
Shoes that are too short force the toes to curl with every step. Over months this contributes to hammer toes, ingrown toenails and bunions — problems that follow a person into adulthood and often require surgery to correct.
⏱️ Kids outgrow shoes faster than you think
Between ages one and three a child can move up a full size every three to four months. Parents who buy one pair per season are often unknowingly sending their child to nursery in shoes a size too small.
📐 Too big is also a problem
Buying two sizes up "so it lasts" makes a child claw their toes to keep the shoe on. That alters gait and balance, and a slipping heel causes blisters. Buy accurate with about 1 cm of room instead.
💬 Children rarely complain
A child's foot is flexible and adapts quietly to a cramped shoe, so there is often no pain signal until damage is done. That is precisely why a periodic measurement, rather than a complaint, should trigger the next purchase.