KidsSizes.co.uk

Sizes for a 4 year old

Clothes, shoes, bike, scooter, helmet and bedtime sizes for a 4 year old, all on one page and taken from UK retailers' own charts.

Checked against UK retailer charts on 18 October 2026.

Clothes
Usually 4–5 years (cut for up to 110 cm at Boden)
Shoes
Typically around UK 9 to 10, but measure their feet
Bike
Balance bike or 12" / 16" wheels
Bike helmet
Kids size, about 48–54 cm head circumference
Duvet
4.5–9 tog depending on season
School uniform
Chest about 24", waist about 20"

Clothes

UK shops label children's clothes by age but cut them to a height. A label like "4–5 years" fits a child from their 4th birthday up to their 5th, so a 4 year old is usually in 4–5 years. Boden prints the maximum height for each label:

Boden girls’ and boys’ body measurements
LabelHeightChestWaist
3–4 yearsup to 104 cmup to 56 cmup to 54 cm
4–5 yearsup to 110 cmup to 58 cmup to 55 cm
5–6 yearsup to 116 cmup to 60 cmup to 56 cm

John Lewis uses single-age labels. Its "4 years" size is cut for the height a child reaches at 4, which is the same as Boden's "3–4". That is why one shop's 4 feels small next to another's 4–5.

John Lewis boyswear and girlswear guides
John Lewis sizeHeightChest (boys / girls)Waist (boys / girls)
4 years104 cm56 / 54.5 cm56 / 54.5 cm
5 years110 cm58 / 55 cm58 / 55 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
4 yearsUK 9–10UK 9

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

Four is the crossover age. Trek puts 12" at 2–4 years and 16" at 4–6 years, so height decides it. Raleigh sizes a 16" for riders from 95 cm tall.

Balance bikeInside legApprox. age (Hornit)
12" balance bike30–46 cm18 months – 5 years
14" balance bike40–53 cm3.5+ years
WheelRider height (Raleigh)Inside leg (Raleigh)Approx. age (Trek)
12"85–98 cm33–41 cm2–4 years
16"95–114 cm41–51 cm4–6 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 and the balance bike size guide.

Scooter

A Mini scooter (Micro: ages 2–5), though Micro suggests a 4 or 5 year old may get more years from the bigger Maxi unless they are small for their age. Whatever the brand, the handlebar should sit somewhere between belly button and mid-chest. See scooter size by age.

Bike helmet

Halfords' guide puts 4 year olds in its Kids size (3+ years), 48–54 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 3/4 yrs age band at:

Item3/4 yrs
Sweatshirts, cardigans, polo shirts, PE T-shirts, blouses (chest)24"
Knitwear (chest)26"
Boys’ blazers (chest)–
Girls’ blazers (ladies’ size)–
Boys’ shirts (collar)11½
Trousers and skirts (waist)20"
Boys’ school shorts (waist)21½"
Jog bottoms (waist)18"

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

Questions

What clothes size does a 4 year old wear?

Usually 4–5 years. Boden cuts that label for children up to 110 cm tall. If they are taller, go up a size.

What shoe size is a 4 year old?

Shoe Zone and Marshmallow Kids put the average at around UK 9 to 10, but foot length varies a lot, so measure in centimetres.

What size bike for a 4 year old?

Four is the crossover age. Trek puts 12" at 2–4 years and 16" at 4–6 years, so height decides it. Raleigh sizes a 16" for riders from 95 cm tall.

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.