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Kids of all ages on bikes

Kids Bike Size Guide

Most of us remember getting our first bike (probably with stabilisers) and how great it felt to explore and discover new places with our friends. 

You want their first bike to be perfect, so to help you, we've put together this kids bike guide covering sizing and a few key tips to ensure you make the right choice. Give them a love of cycling for life and inspire healthy habits they can take into adulthood.

Approx. Age

Height (cm)

Wheel Size (inches)

2 - 4

85 – 105cm

Balance / 12"

4 - 6

105 – 117cm


5 - 7

112 – 125cm


6 - 8

117 – 132cm


7 - 10

125 – 136cm





How to choose the right size bike?

Choosing the right size bike for your child is the most important thing. 

Kids bikes are sized by their wheel diameter and range from 10" to 24". 

The easiest way to get the correct size for your child is by measuring their height and checking our size chart.

For adult bike sizing info see our bike sizing guide.

Chart showing kids wheel sizes and ages

Golden rule: Choose a bike that fits

Avoid buying a bike which is too big for them with hopes they will 'grow into' the frame. It will be too heavy for them, difficult to ride and potentially dangerous to use – and safety is key. 

You want them to easily reach the floor and pedals, and have full control of the handlebar and brakes.

A larger bike will be heavier and harder to manoeuvre, which is less fun to ride. Enjoyment is the determining factor that will get your kids to love cycling.

Remember, you can always hand down bikes to younger siblings once they've outgrown their bike, or simply sell them on.

Types of kids bikes

12 inch bikes and balance bikes

2 – 4 year old's bikes

12" bikes & balance bikes

These bikes come in two types, pedal bikes with stabilisers and balance bikes.

Balance bikes are great first bikes for toddlers as they build balancing, co-ordination and steering skills quicker than if they use stabilisers – which are crucial for their development. Also, there are no moving parts (except wheels) so they're less likely to get tangled up in a fall. Your child can also skip the stabiliser stage altogether.

Bikes with stabilisers come with a range of accessories such as baskets, dolls seats and brightly coloured designs to appeal to little riders.

Kids riding a 14 inch and 18 inch kids bike with their family

4 – 8 year old's bikes

14" – 18" bikes

We're leaving balance bikes and stabilisers behind and transferring to pedal bikes. These bikes come with pedals, brakes and single speed drivetrains. They're built from durable materials like steel or aluminium which can take the demands of energetic use.

The addition of brakes, riser bars and sturdy grips improve safety at faster speeds while a low top tube (the bar between their legs) makes dismounting easier. 14-18" bikes give them their first real taste of proper cycling while building key skills.

Two 20 inch kids bikes on a cycle path

7 – 10 year old's bikes

20" bikes

These are coming of age bikes with geared drivetrains and good quality components. Most 20" bikes will be mountain bike orientated with front suspension.

You don't tend to start seeing on-road style bikes until you get to 24" wheels. 20" bikes are ideal for more adventurous family rides through the park, on canal towpaths and up fire roads.

Front suspension helps to soak up some of the lumps and bumps for a more efficient and comfortable ride. Strong wheels with tacky, knobbly tyres improve stability too.

Three kids riding 24 inch junior bikes on a canal towpath

10 – 12 year old's bikes

24" (junior) bikes

24" bikes mark the last stage in your child's development before the move to an adult bike. They're scaled down adult bikes. You find proper gearing and refined frame designs. This is where you start seeing a split between off-road and on-road bikes.

On-road bikes will feature lightweight frames (aluminium at the higher end) and stiff rigid forks for speed on flat roads and tarmac. Off-road bikes come with 50-70mm front suspension for rougher terrain.

7-9 speed cassettes help your child get to grips with gearing and learn how to ride efficiently.

Buy the best bike you can afford

It's worth choosing your budget carefully and buying the best bike your budget allows. Why? It all comes down to weight. Kids bikes can be very heavy with cheaper options made from steel. Weight matters more so on a kids bike than on an adult bike because children as smaller, lighter and have less muscle mass. Shaving weight off the frame will make a huge difference to handling, responsiveness and enjoyment.

More expensive kids bikes have refined frames with less material being used, whilst keeping them durable. The switch from steel to aluminium which is lighter, stiffer and just as strong as steel will make a big difference to ride characteristics.

Brands like Frog and Early Rider specialise in building kids bikes and produce lighter bikes than most of their competitors.

Choose a design they'll like

No matter how good your choice is, if they don't like the look of it you'll have a hard time keeping them in the saddle. We stock a range of boys bikes and girls bikes in a range of colour schemes and designs to appeal.


Choosing the right kids bike is very important. It'll leave a lasting memory and will be a big factor in whether they choose to continue cycling into adulthood. By choosing the right size for your child's height, and by opting for the best your budget can afford, you can't go far wrong.

Remember, fun and enjoyment is everything. Buy a bike which is properly fitted to their size so they can cruise around in comfort. Lastly, get them to always wear a helmet!

Most popular kids bikes