Kids bike sizes | How to measure a bike frame | Argos


Buying a kids bike online to be delivered or collected in store is easy and convenient - and especially useful if it's a surprise present.
We'll show you how to choose the right wheel sized bike for your child to ensure safe and easy riding from the get go.

Shop all kids bikes

How to measure bike size

Unlike adult bikes, kids bikes are sized according to wheel diameter. Here's how to find the right wheel size for your child.

Balance bikes

Beginner Bikes

Bikes for big kids

Measure their inside leg

With your child standing straight measure from the inside arch of their foot up to their crotch. Note down in inches.

This can be fiddly for little ones, so try this; standing against a wall, get your child to place a thin book between their legs as far as it will comfortably go. Put a sticky note where the top of the book is on the wall. The child can move away so you can measure from this point to the floor.

Convert measurement to wheel size

Inside leg measurement (inches) Suggested wheel (inches) Average age range Cycling ability  
<13" 10" 2 to 3 Early starters just beginning to get
their balance on a bike.
Shop balance & 10" bikes
13"-15" 12" 3 to 4 Beginner bikers using stabilisers. Shop 12" bikes
15"-17" 14" 4 to 5 Confident using stabilisers and
learning to ride without stabilisers.
Shop 14" bikes
17"-19" 16" 5 to 6 Probably confident without stabilisers,
but these can be added if necessary.
Shop 16" bikes
19"-21" 18" 6 to 7 Riding without stabilisers. Shop 18" bikes
21"-24" 20" 7 to 9 Confident riders. There's more variety
in the bike styles available, i.e. BMX,
hybrid and mountain bikes if
they're exploring different styles.
Shop 20" bikes
24"-28" 24" 9 to 11 Confident riders. There's more variety
in the bike styles available, i.e. BMX,
hybrid and mountain bikes if
they're exploring different styles.
Shop 24" bikes

Not sure on their height?

Shop our range by age, based on average heights we'll show you our range of suitable bikes.

Moving on to adult bikes

Once your child has grown out of a 24" bike, they're ready to move to an adult bike. These are sized by their frame, rather than wheel size.

See our adult bike guide to find out more.

Take me there

Shop adult bikes

How you'll know it's the right wheel size

A few visual pointers to help you know if the bike is the right wheel size for your child.

The right wheel sized bike...

Sitting on the seat, they should be able to touch the tip of their toes to the ground, without leaning to either side. When riding, their legs should be almost straight (but not locked) on the downstroke.

It's too big if...

They can't reach the floor when sitting on the seat without leaning the bike to one side. It's also not right if they are leaning forward and stretching out over frame with their arms locked.

It's too small if...

Their legs are still significantly bent at the knee when on the downstroke of the peddle. They may also have a bend in the arms and ride in a very upright position.


Our range of bike safety essentials, training aids and fun accessories.

How to assemble a child's bike.

Let us share our simple steps for putting a child's bike together.

Why buy at Argos?

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