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What Size BMX Bike Do I Need? Check out All Brilliant Secrets Here!

Written by Gary Johnson / Fact checked by Henry Speciale

what size bmx bike do i need

Are you curious what’s the right BMX size for you? This is a common concern among bikers, especially those who just started off.

They usually ask, “what size BMX bike do I need?” Well, the answer is simple. Having some knowledge of sizes and dimensions will help you determine what bike size goes along with you. Your height also plays a part in knowing the precise measurement.

Having one that fits perfectly to your height allows you to stay comfortable throughout the ride.


What Size BMX Bike Do I Need


Getting the right size for you depends on your reach and height, as BMX bikes usually have one frame size that sometimes varies in length.

For people with a height of 110 to 122 cm, the suggested BMX wheel size is 16 inches. This is the ideal one for children five to seven years old.

On the other hand, a BMX bike for 10 year old is different. Children from seven to 11 years old that are 122 cm to 147 cm in height are good to have a wheel size of 18 inches. While people with a height of 147 cm to 193 cm can have BMX bikes 20 inch.

There’s also a big difference between BMX bikes for mens size and those bikes for women. Women’s bicycles usually come with shorter stacks as they have shorter torsos and reach compared to men.

When choosing a BMX bike frame size, it is vital to prioritize comfort. Ensure that you can stand over the frame having a minimum gap of 2 cm between the top tube and your body.

Therefore, an inside leg’s minimum height of 23 inches is needed for you to stand on a full-size BMX bicycle. This is both applicable for adult BMX bike sizes and for younger ones.

Sizing Guide

There are several sizing guides and charts that you can use as a reference. Everything depends on your height and age. So, I highly suggest precisely measuring your peak. Constantly checking the measurements provided by the manufacturer is also important.

Plus, it doesn’t hurt to ask for some additional help from experienced staff members of a particular shop that will guide you in having the right BMX size.

What makes size adjustment easier for BMX bikes is the wheel size that can be changed. Riders can choose the wheel size to adjust the overall height of the bike. It can also help go along with your height and age.

Various sizes and styles are used for different purposes, like racing and doing tricks. That is the reason why there are different categories like Sprint BMX and Freestyle BMX.

Measuring BMX Bikes


This is the common challenge when it comes to looking for the proper size – measuring the bike. The only rule of thumb in choosing your BMX size is to ensure that you can stand firmly over the bike frame.

Note that a full-sized BMX bike has a 20-inch wheel. However, there are always smaller sizes available for children and other younger bikers.

How Right is the Right Size

People often think of BMX bikes as simple ones. In fact, it is even hard to tell the difference between each bike. But the truth about a BMX bike lies in its engineering and structure, which makes it capable of enduring tough challenges.

Size is an important matter for wheels and top tubes. It is one thing that you must prioritize to know how “right” your chosen wheel size to go along the bike frame is. Just remember that the quote “bigger is better” does not really apply to this.

If you are confused about the right size to choose, you can always find someone with a similar body build and height as you. Ask for a secondary recommendation from someone with a similar measurement as you.

Asking their size frame would really help a lot. We never know, though. They may even let you test ride their bicycle to help you determine if the sizing is good for you too.

Know Your BMX Bike

There are various wheel sizes available for BMX Bikes. It is available in 12 inches, 14 inches, 16 inches, 18 inches, 20 inches, and 24 inch BMX. However, the most commonly used is 20 inches, just like the Mongoose BMX Bike with 20-inch wheels.

You can also check this video to know more about the right BMX size for you. It will help you learn a lot.

Top Tube Measurement

Aside from measuring the wheel size, top tube measurement is also crucial when getting a new bike size. In fact, it is even more vital than wheel size. A 24” BMX bike has a relevant top tube length to wheel size ratio.

This also goes the same for BMX bikes with wheels that range from 12 inches to 18 inches. In fact, there’s a recommended frame dimension chart for top tube measurement, too.

It’s filled with all given sizes, from micro-mini to Pro-XL. This guide also has accurate top tube measurement and the corresponding height that goes along with it.

As a guide, you can also video or capture yourself and look at how you drive your bike. Observe if you tend to ride over the prow, or if you hit the bars occasionally.

Being uncomfortable and having a cramped feeling is also a sign that you need a bigger bike frame.

This subject is hard to recommend because of the various components of a BMX bike, which may influence the whole performance and sensation of the bicycle. There are times that you might feel a bike frame is small, but that is usually caused by a jazzy stem measurement.

Your biking style also plays a part. It can assess the ideal size frame that best complements it.

Importance of Top Tube

A bike’s top tube, or also known as TT, is the part that connects the BMX bike frame to the bike’s front section and to the seat post tube. Various sizes also tend to slightly overlap, serving as a starting place in looking for the right frame for you.

Choosing a frame is a significant buy you decide on because this one is considered as your build’s centerpiece. I highly recommend getting the accurate one. However, before you can do that, you can test ride the bicycle first.

Going to a local bike store nearby can also be a great help. You can visit shops and ask the same query about this concern. They are the best option because of their knowledge in the said field. They are happy to assist you in sizing up.

A Few Things to Remember

Sizing up in person becomes totally preferable if you plan on going to a bike shop. Some people try sizing up a bike frame through the phone, but I can tell that this method is ineffective.

Of course, it takes trial and error just to get the accurate fit for you. Getting it right is not impossible, though. All you have to do is ensure that the bike frame is found in the sizing’s right ballpark.

You can also do additional changes or modifications that will help tailor and polish your fit. Consider the stem measurement, as well as the handlebar position of your BMX. Also, take note of the following tips that will help modify your setup.

Do note that every 6 mm of a stem length equates to one-fourth inch. And the best option out there is to try out the tiniest stem in the list. This will ensure that the navigation is smooth. That’s because the lengthier the stem, the higher the feeling of oversteering.

The next thing to talk about is the bar position. This is important if you like your handlebars parallel to your head tube angle, promoting accurate handling. Besides that, you can pull them back a bit, bringing the bars back to give a shorter biker space.

However, always remember that going back too far is not advisable as it may start to be uncomfortable for you.

This also goes the same for going forward, where you can always push them slightly. As long as you remember not to go past the vertical on the handlebar set up, you can always find the right size and setup for your BMX size.

Read more: Cost to build a BMX bike.


And that’s all that you need to know when it comes to the question ‘what size BMX bike do I need’. Of course, there are a few key points to remember which will aid you in your journey.

But there are also good BMX bikes with universal sizes, like the Mongoose BMX Bike for children. Bikes like this help you pick the right size easier.

  • The right BMX size allows you to stand firm over the bike frame with no issues.
  • Remember the importance of top tube measurement.
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