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Kids Bike Sizes – Choose The Right One

Jeff Balton

Kids Bike Sizes

Ordering bikes for kids online is becoming more and more popular nowadays. It is because there are no shop-keeping or warehouse costs, which makes the prices even lower!

And since everything is moved online, you don’t have to try your bike first. Other people have done it for you.

You should try your bike first! FALSE

I’ll show you four methods you can use to find the right bike size for your child.

NB! Ordering a bike online for a kid is much easier than for grown-ups.

Feeling more confident?


So if you have questions about kids’ bike sizes, here are the answers!


Method 1: Age & Wheel Size

Level: Simple (Not so accurate)

A lot of parents ask us questions such as “What size bike for a 4-year-old?”, “What size bike for a 6-year-old?” or “What size bike for a 7-year-old?”.

The reason why these questions are so common is that choosing the right kids’ bike size based on age and wheel size is the simplest method around. Basically, the idea is this: Smaller kids ride bikes with smaller wheels and bigger kids ride bikes with bigger wheels.

Another common question is, “26-inch bike for what size person?” We’ve explained why this question is flawed in our guide linked here.

Related: 24-Inch Bike for What Size Person?

With that said, you can get a rough estimate of how a bike will fit a child by considering the wheel size, which you can see in the size chart below.

2-4 3-5 4-6 5-8 7-9 8-11 10-14
Wheel Size 12-inch bike 14-inch bike 16-inch bike 18-inch bike 20-inch bike 24-inch bikes 26-inch bikes

As a result: Now you know how to measure a kid’s bike by selecting the right wheel size.

This method works in the majority of cases as kids generally grow at the same pace. However, as always in life, there are exceptions to this rule.

If you are afraid that your child is taller or shorter than the average for their age, then you can use the…


Method 2: Standover (Inseam) Height Method

Level: Better

How to measure kids leg inseamThis is another very simple method of determining kids’ bike sizes, though it takes a bit more effort.

What you need to do first is measure your kid’s leg inseam. It takes only 30 seconds and all you need is a tape measure.

  1. With shoes on, have your child stand with feet slightly apart.
  2. Measure the height from the ground up to the crotch.


That’s the leg inseam.

Keep in mind that you might need to convert the result into inches if you measured it in centimeters (cm). To do that, just divide your result by 2.54 (for example, 40cm equals 15.75 inches).

Moreover, different bikes require different saddle heights. Bikes for teens and a toddler bicycle will differ greatly in this regard. The best method to find the right saddle height is by using the leg inseam measure.

Related: Best Bikes For Teenagers

As a result: Now you know how to measure a bike size for kids based on their standover height. Scroll below to find the right saddle height.

Why is the standover height that important? With the right standover height, your kid will be able to get off the bike whenever necessary and feel stable and in full control. There’s nothing worse for confidence than a bike that feels too big and doesn’t let you touch the ground with your feet.


Method 3: Kids Size Chart

Level: Good!

How to size a bike for a kid with more certainty? Consider several methods all at once.

If you want to make sure to choose the right kids’ bike size, you should take into consideration 1) Age, 2) Height, 3) Inseam, and 4) Tire Size.

We tried to gather all of this data into one kids’ bike size chart that you can see below. It should work for most kids, except for some exceptions.

Height (Inch) Height (cm) Leg Inseam (Inch) Leg Inseam (cm) Tire Size
2 2’9″ – 3’1″ 85-90cm 12″ – 14″ 85 – 90cm 10″
3-4 3’1″ – 3’3″ 90-100cm 14″-17″ 35-42cm 12″
4-5 3’3″ – 3’7″ 100-110cm 16″-20″ 40-50cm 14″
5-6 3’7″ – 3-8″ 110-115cm 18″-22″ 45-50cm 16″
6-8 3’8″ – 4’0″ 115-120cm 20″-24″ 50-60cm 18″
7-9 4’0″ – 4’5″ 120-135cm 22″-25″ 55-63cm 20″
9-11 4’5″ – 4’9″ 135-145cm 24″-28″ 60-72cm 24″
11-14 5’+ 145cm + 28″+ 72cm+ 26″

As a result: You can double-check the results. If you’re satisfied, you can choose the right bike based on these results.

If you find that some numbers don’t match and you’re getting different results based on different criteria, keep in mind that all kids are different. As they get older, the discrepancies between individuals become even larger. 

If you’re still getting different results and you can’t make a choice, check out the last method:


Method 4: From A to Z

Level: Best

Sometimes, choosing the right kids’ bike size based only on one method can be confusing. You can get results that don’t add up and just make things worse than before (though that’s rare).

If you want to double-check your results or just make sure you are getting the most accurate results possible, then follow the steps below:

  1. Measure the inseam (second method).
  2. Choose the right bike size based on age and wheels (first method).
  3. Choose the right type: Balance / Training Wheels / Pedal Bike.


NB! We don’t suggest going for a kids’ bike with training wheels.

Balance bikes provide a much better and more natural learning platform. Training wheels give a false sense of security and don’t really allow kids to learn how to balance on two wheels on their own.

Kids learn most quickly and most easily when moving from a balance bike straight to a pedal bike.


Right Saddle Height (vs Standover Height)

Right Kids Saddle height

Choosing the right saddle height is extremely important for all riders, especially for kids. If you place the saddle too low or too high, your child is likely to feel a lack of control and lack of confidence.

The right saddle height differs from one situation to another, depending on the type of bike used. Here’s a rough guide you can follow:

  • Balance bikes – The seat should be 1″ to 1.5″ below the child’s inseam.
  • Training wheels – 0 – 3″ above the child’s inseam.
  • 1st pedal bike – The saddle height should be the same as the child’s inseam.
  • Next pedal bike – 2″ to 4″ above their inseam.


This is important to keep in mind to improve the stability and comfort of your kid on the bike. It’s important for them to be able to touch the ground with their feet without getting hurt.

Otherwise, they might feel unstable or lack confidence.

NB! Always wear a helmet! See our top bike helmets for kids



You can find the right size bike by referring to a bike size chart for kids. There are different methods you can use to determine the right size, the most popular of which are inseam length, age, and tire size. Using the inseam length method is the most reliable one.

The first thing to consider is your child’s age. For example, a toddler bicycle and bikes for teens have different components and are differently sized. If your child doesn’t know how to ride, get them a balance bike first, and then a pedal bike with or without gears.

You can buy your child a bike as soon as they are 18 months old. Of course, at this age, a small balance bike is the best choice. Once a child is 3-4 years old, they can start riding a pedal bike, since at this age their coordination and muscle control improves significantly.

To find the perfect size bike for your child, you need to take a close look at a bike size chart for kids, such as the one we have in this article. It will tell you which size to choose based on your child’s age or inseam length. To ensure you make no mistakes, it’s best to combine these two methods.

Three-year-olds should typically ride a bike with 12" or 14" wheels, assuming their inseam height is 14"-17" long and they are 3’1″ – 3’3″ tall. However, keep in mind that these are just rough figures and that you should take a look at our full kids' bike size chart for more information.

Four-year-olds should typically ride a bike with 14" or 16" wheels, assuming their inseam height is 16″-20″ long and they are 3’3″ – 3’7″ tall. However, keep in mind that these are just rough figures and that you should take a look at our full kids' bike size chart for more information.

Six-year-olds should typically ride a bike with 16" or 18" wheels, assuming their inseam height is 18"-22" long and they are 3’7″ – 3’8″ tall. However, keep in mind that these are just rough figures and that you should take a look at our full kids' bike size chart for more information.

Seven-year-olds should typically ride a bike with 18" or 20" wheels, assuming their inseam height is 20"-24" long and they are 3’8″ – 4’0″ tall. However, keep in mind that these are just rough figures and that you should take a look at our full kids' bike size chart for more information.


To Wrap It Up

SuggesteAt first, choosing the right size bike for kids might seem daunting and complicated. But it isn’t. In most cases, it should be easy to find the right size by using only the first method.

However, to make sure you are getting the most accurate results, we recommend going through all four methods presented in this kids’ bike size guide. That way, you will 100% end up with the right size.

Therefore, when it comes to buying kids bicycles, trying the bike out before purchasing is not necessary. Just follow the steps above and you will be good to go!


  • Gina says:

    Hi. My son has outgrown his first bike. He is 4’4″ with a 22″ inseam. He turns 9 in a few weeks. We want to order a bike, but with COVID, we can’t go in and try out. We think maybe 20″, but he is also close tonthe criteria for 24″.

    What do you suggest?

    • Jeff Balton says:

      Hi Gina,
      It’s always case to case and children don’t really have the ‘perfect’ fit. You can still make adjustments in terms of saddle height. A 22″ can be a comfortable fit for him. Check out our:
      Kids Bike Sizes

  • jacqueline says:

    I have a 10yr old son 4’9” and a 14 yr old daughter. They haven’t learn how to ride a bike. what’s the best type to learn? Also, my daughter tried my bike and states seat is uncomfortable what type of seat is recomendable? She’s 5’2” weight 175lbs.

  • Natasha says:

    Hi, I have a question, our daughter is almost 11yo, she is petite. Her height is 4’2.5” and her inseam 24”. She is in between 20” and 24” sizes. What would you recommend? Thank you

    • Jeff Balton says:

      She is at an age when she will probably start growing rapidly, so I’d go for a 24″ kids bike. No point in getting a 20″ bike that’s perhaps going to be too small for her in a few months or a year.

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