KidsSizes.co.uk

Sizes for a 9 year old

Clothes, shoes, bike, scooter, helmet and bedtime sizes for a 9 year old, all on one page and taken from UK retailers' own charts.

Checked against UK retailer charts on 18 October 2026.

Clothes
Usually 9–10 years (cut for up to 140 cm at Boden)
Shoes
Typically around UK 1 to 2, but measure their feet
Bike
20" or 24" wheels
Bike helmet
Juniors size, about 52–59 cm head circumference
Duvet
4.5–9 tog depending on season
School uniform
Chest about 30", waist about 26"

Clothes

UK shops label children's clothes by age but cut them to a height. A label like "9–10 years" fits a child from their 9th birthday up to their 10th, so a 9 year old is usually in 9–10 years. Boden prints the maximum height for each label:

Boden girls’ and boys’ body measurements
LabelHeightChestWaist
8–9 yearsup to 134 cmup to 67 cmup to 60 cm
9–10 yearsup to 140 cmup to 70 cmup to 62 cm
10–11 yearsup to 146 cmup to 74 cmup to 64 cm

John Lewis uses single-age labels. Its "9 years" size is cut for the height a child reaches at 9, which is the same as Boden's "8–9". That is why one shop's 9 feels small next to another's 9–10.

John Lewis boyswear and girlswear guides
John Lewis sizeHeightChest (boys / girls)Waist (boys / girls)
9 years134 cm67.5 / 61 cm68 / 60 cm
10 years140 cm71 / 63.5 cm71.5 / 62 cm

If they're between sizes, go by height first, then chest for tops and waist for bottoms. More on this in kids’ clothes sizes by height.

Shoes

Two UK shoe shops publish an "average size by age". They don't quite agree, so you get a range:

AgeShoe Zone averageMarshmallow Kids chart
9 yearsUK 1–2UK 1

Feet vary more than height does, so measure heel to longest toe in centimetres and use the kids’ shoe size chart by foot length. Buying a European brand? Use the EU to UK shoe size converter.

Bike

Nine is when many children move up to a 24". Trek lists 24" for 9–11 years and 130–150 cm; Raleigh for 128–143 cm. A child under about 128 cm is usually still on a 20".

WheelRider height (Raleigh)Inside leg (Raleigh)Approx. age (Trek)
20"114–129 cm53–63 cm6–8 years
24"128–143 cm57–68 cm9–11 years

Cycling UK's rule of thumb: the wheel diameter in inches should be no bigger than the child's inside leg in inches. Full tables in the kids’ bike size chart.

Scooter

A larger "maxi" style scooter or a two-wheeler. Micro designs its Maxi for ages 5–12. Whatever the brand, the handlebar should sit somewhere between belly button and mid-chest. See scooter size by age.

Bike helmet

Halfords' guide puts 9 year olds in its Juniors size (7+ years), 52–59 cm. Helmets are sized by head circumference, not age, so measure about two finger-widths above the eyebrows. Fit checks are in the helmet size guide.

Bed and duvet

Dunelm suggests 4.5–9 tog for children over three, depending on the season: about 7.5 tog in winter and 2.5–4 tog in summer. A single bed takes a 135 × 200 cm duvet.

More detail in what tog duvet for a child. Pyjamas follow the same age labels as clothes: see kids’ pyjama sizes.

School uniform

Uniform is often sold in inches. Your School Uniform's chart puts the 9/10 yrs age band at:

Item9/10 yrs
Sweatshirts, cardigans, polo shirts, PE T-shirts, blouses (chest)30"
Knitwear (chest)32"
Boys’ blazers (chest)30"
Girls’ blazers (ladies’ size)8
Boys’ shirts (collar)13
Trousers and skirts (waist)26"
Boys’ school shorts (waist)26½"
Jog bottoms (waist)24"

Full chart and how to measure: school uniform sizes explained.

Questions

What clothes size does a 9 year old wear?

Usually 9–10 years. Boden cuts that label for children up to 140 cm tall. If they are taller, go up a size.

What shoe size is a 9 year old?

Shoe Zone and Marshmallow Kids put the average at around UK 1 to 2, but foot length varies a lot, so measure in centimetres.

What size bike for a 9 year old?

Nine is when many children move up to a 24". Trek lists 24" for 9–11 years and 130–150 cm; Raleigh for 128–143 cm. A child under about 128 cm is usually still on a 20".

Where these numbers come from

Checked 18 October 2026. Brands change their charts, so always check the size guide of the shop you're buying from.