Kids Bike Sizes Guide- How to Find the Perfect Kids Bikes

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Kids bike sizes can vary greatly. If you thought that buying a bike for an adult is complicated, the world of children’s bikes can seem like a labyrinth. For grown men and women, getting your inseam and torso length will lead you to a bike that is the right size with only a few adjustments necessary.

When it comes to kids there is more to take into account. This is because children, although the same age, can be very different. You may find two five year olds, for example, and one will be very small and the other quite tall. These two kids will definitely not be served by the same bike.

There are other factors that make buying a bike for your child complicated. Some manufacturers go according to wheel size – if your child is such and such a height, their correct wheel size will be such and such. If only it were so easy. While sometimes you can get correct kids bike sizes this way, manufacturer wheel sizes are not standard.

A quick comparison of the charts will reveal that some manufacturers recommend bigger wheel sizes and others smaller ones for children who are the same height. So, what should you take into account when you are buying a bike for your child? We will try to make it as simple as possible.

Bike Sizes for Kids – Kids Bike Sizes Guide

There are several different bikes that you can choose for your child depending on their age and riding ability. Really young children (2 – 5 years) need balance bikes, 3 – 6 year olds may need a bike with training wheels, or they may jump straight to basic small wheelers depending on how well they are able to balance.

At around the age of six, if your child is active, enjoys riding and has learned to balance properly you will be looking at a bike with gears and a suspension. For these kinds of bikes you want to focus on a bike that can negotiate steep terrains around your neighborhood and in the park, and one that isn’t too fast as you don’t want your child getting into accidents.

Now, you may think that your little girl wants a pretty princess bike, but she may feel that she is ready to try out something heavier and sturdier like a mountain bike. When you are choosing a bike for your child let them be a part of the process so that they can appreciate and fully utilize their new present.

It is now time to take your child’s measurements. For a bike the most important is the in-seam. That is the length from the crotch to the foot. Get them to stand with their legs astride parallel with their shoulders, feet flat on the ground. You should also measure their full height as some bike size charts for kids include full height. If your child is still in diapers take it off before you take the measurement.

Think about your child’s weight. Some kids are biggies and they require a sturdy bike while others are spindly and will do okay on lightweight bikes.

Kids Bike Size

Basic Bike Size Chart Kids in Inches

Kid’s Age Height Inseam Wheel Size
2 – 3 years 2 ft 10 inch – 3 ft 4 inch 14 – 17 inch 12 inch
3 – 4 years 3 ft 1 inch – 3 ft 7 inch 16 – 20 inch 14 inch
4 – 5 years 3 ft 7 inch – 4 ft 18 – 22 inch 16 inch
5 – 8 years 4 ft – 4 ft 5 inch 22 – 25 inch 20 inch
7 – 11 years 4 ft 5 inch – 4 ft 9 inch 24 – 28 inch 24 inch

You may find that some manufacturers sell their bikes according to age and wheel size, and they will give you a kids bike size chart that looks like this:

Age Wheel Size
2 years 10 inches
3 – 4 years 12 inches
4 – 5 years 14 inches
5 – 6 years 16 inches
6 – 8 years 18 inches
7 – 9 years 20 inches
9 – 11 years 24 inches
11 – 14 years 26 inches

If you look closely at this chart you can immediately see that you will soon run into hurdles. What if, for example, your child is between 6 and 9 years old? There are two wheel size options provided so which one should you choose?

Also, your child may be 5 years old but rather shorter than other children her age, so what wheel size is best for her? While this second chart can provide some guidance when it comes to kids bikes, it is rather rudimentary, and if you are buying a bike online you really don’t have much to go on.

It is best to use the chart that includes the inseam measurement, and if you can find one that also lists the full height of the child it may be even more accurate. You can check out bikes for 3 years kids

What else to consider for bike sizes for kids

You have your child’s inseam and full height, but that is not enough if you want to get a bike that your child will ride with ease and that they will be safe on. Before you buy, look into the following:

  • How heavy is the bike? Children’s bikes can be just as heavy as adults. The problem with this is that if the child falls and the bike falls on top of them it can cause more than just a few bruises and scratches. If you look carefully you will find kids bikes that are lightweight and engineered for safety.
  • Should you take into account how fast your child is growing? Bikes aren’t cheap and you may think that buying a bike that’s a size bigger is a good way to save money. Unfortunately, bikes aren’t like clothes – they are more like shoes. A size too big and it will be difficult and awkward for your child to move around, not to mention that it increases the odds of your child getting into accidents. When it comes to children’s bikes you should buy the right size for their age and height. When they outgrow it you can sell it off and use the money towards their next bike.

Saddle height is very important when it comes to bike sizes for kids. If the saddle is too big your child will keep sliding off and too small and they will feel cramped and it may even hurt to ride the bike. The saddle should be just the right size and adjustable so that your child’s feet are able to flatly touch the ground when they come to a stop.

  • It is important to talk a little more about how your child’s feet should rest when they are on the bike. Why is it important that they are able to step on the ground properly when they are sitting on the bike? So that, as they are riding, in case they need to stop and cannot get to the brakes on time they can use their feet to stop. They shouldn’t have to tip the bike to one side to get on or off it.  
  • Does your child like the bike? This may not seem like a big deal. When you were growing up your parents bought whatever bike they wanted for you and you took it, thanked them and happily used it. Today it is a little different and kids are hard pressed to fit in and impress their peers. If your child doesn’t like the bike that you buy them they may never use it and you may put them off riding for the rest of their lives.

Does the bike have lights and reflectors? This may not be important if your child is still young but as they get older they may need to ride after dark. It is very important that you choose a bike that is made with safety in mind – it should have visible reflectors (check them out for yourself after dark) and good lights.

  • What bike equipment and accessories do you get with the bike? You can choose to buy a standalone bike with no equipment or accessories, but remember that you will have to spend money on these items anyway, so it is best to buy a bike that comes with a helmet and a chain guard. There are some that come with a lot more but they cost a pretty penny.

Kids Bike Size Chart

What is better? A road bike or a mountain bike?

Most bikes for young children are mountain bikes which makes them perfect for different kinds of terrains – your child can ride on pavement and tarmac with ease and when they want to use their bikes in the park they will not have any problems.

They also have thick tires which makes them more stable. However, there are road bikes available for children and you may be wondering what their benefits are. The primary benefit of a road bike is that it is excellent if you are riding on smooth surfaces all the time.

Road bikes are also more aerodynamic than mountain bikes, which means that your child can ride faster. Generally, it is best to let your child use a mountain bike until they are well into their teenage years when they are better riders. If, however, your child will never need to ride on a rough surface you may want to get them a road bike which doesn’t go too fast.

Cycling with your kid should be fun. Check out our guide on bike size chart for adults 

What if I get the wrong kids bike size?

This isn’t uncommon especially if you are buying your kid’s bike online. You should buy from a vendor who allows you to return and get a bike in the right size. You can minimize the risk of error by talking to a bike expert in your neighborhood. Take your child’s measurements to them and have them recommend a bike size.


Kids bike sizes can be quite confusing especially if you are a first-time buyer, but you can get the right bike if you use a bike size chart kids that includes the inseam and height measurements. The most important thing to keep in mind is safety; getting a bike in the proper size will go a long way to ensure that your child is safe and that they become expert riders.