What Size of Child's Bike Do I Need?

children's bike sizing, kid's bike size, what size bike should I buy -

What Size of Child's Bike Do I Need?

We wrote a guide to which bike size do you need the other day, and it is only fair we also offer a kid's bike size guide as well. Once you've looked at the chart, we have a few other pointers for you below it. Have a look and as always double-check a manufacturer's size chart if it is available.

Child's bike size chart

Wheel Size 

Child's Age 

Height of Child 

Inside leg of Child 

12" (Balance bike) 

3 - 5 

3' 3" - 3' 8"

30 - 40cm 


4 - 6 

3' 5"- 3' 10"

36 - 44cm 


5 - 8 

3' 8" - 4' 2" 

40 - 54cm 


7 - 9 

3' 10" - 4'' 6" 

52 - 59cm 


8 -11 

4' 2" - 4' 9" 

57 - 66cm 


A few pointers to getting a kid's bike

If you utter the words, "They'll grow into it," you are buying the wrong size bike. Yes, kids grow. Yes, they tend to be inopportune when they decide to have a growth spurt. 

That does not mean you should buy a bike that they will grow into. Simply put, you are putting your kid in danger. They will not have proper control. Reaching the bars and brakes won't be fun, and you'll be putting your child off cycling.

I'm sure at this point we'll hear the "My parents let me grow into a bigger bike and it never did me any harm," honestly, don't be that person.

How long will it be until my child outgrows this bike?

We get this question a lot. We can't answer it though. We can give an estimate, but we can't be held to it. There are two many variables at play here to provide you with a correct answer, and many of these variables we'll never know no matter how many questions we ask you.

We can though tell you when your child has outgrown their current bike. If your child looks to be pedalling awkwardly, with their knees trying to touch their ears and their elbows sticking right out, then without a doubt the bike is too small.

Your child needs a small bend at the elbow, and you won't get that on a bike that is too big as well as too small. The bend here is essential. It is the bend that allows your child to control their bike and also it acts as a little bit of suspension.

Look at your kid's feet, are they pushing out sideways at the bottom of the pedal stroke? If this happens, the saddle height is too low, or the bike is too small. If it is the saddle height, raise it until the issue has gone. Watch out for the minimum insert marker on the seat post. If you go past this, then it is time for a new bike.



Leave a comment

Please note, comments must be approved before they are published