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Does BMX Size Matter? (Explained for Beginners)

BMX bikes are very popular. They are used by children, adults, and also professional riders. BMX bikes come in several wheel and top tube sizes. It has a common size of 20-inch wheels with 20-inch frames. Most of them can look similar to you. So, does size matter? 

Does BMX size matter?

Yes, they do. The sizes of BMX bikes are set according to the height and age of the rider. The frame and wheel size change based on that. The greater the height of the rider, the bigger the size. BMX sizes are also influenced by the weight and experience of the rider.

Without the correct size, you won’t be able to reach your optimum comfort level. It’s better to select the size that matches you and your preference. The bike size changes everything starting from the way your bike rides, stunts you can do, your balance, and how you lift.

Are BMX all the same size?

No. BMX bikes tend to look small because of their popularity among kids. But it is a common misconception to assume that they are all the same size. 

They come in various frame sizes as well as wheel sizes. There are at least 8 categories of sizes made for different heights and weight. There are custom sizes available too. 

The difference is not too much. The size difference is only a few inches between a child who is 10 years old and a tall professional rider. It’s not the age that matters, it’s the height. 

What sizes do BMX bikes come in? 

They typically come in 8 categorized sizes, they are Micro Mini, Mini, Junior, Pro, Pro XL, Pro XXL, Pro-XXX, and Cruiser. 

Micro Mini: 

It has a wheel size of 16 inches and a bike frame size of around 15 to 16 inches. This is best for children who are 6 to 10 years olds and are 4 feet tall or below that. The estimated rider weight for this size is around 40 to 70 pounds.


This category has a bike frame size of 16 to 17 inches. The wheel size is generally 18 inches. This is also for children. Mainly for 10 to 13 years old children. who are between 120 cm to 140 cm in height. It is made for riders who are 70 to 82 pounds. 


Junior has a bike frame size of 17 to 18.5 inches and a wheel size of 20 inches. They are used by children under the age of 13 who are around 80 to 90 pounds and are at least 4 feet and 4 inches in height. 


This is for intermediate-level riders who are around 4’8 to 5’4 inches in height. It has a wheel size of 20 inches and a bike frame size between 18.5 to 19.5 inches. The suitable rider weight would be 88 to 100 pounds.


This is a popular category that has a bike frame size and wheel size of 20 inches. They are for teenagers and adults. They should be above the age of 15 due to safety concerns. The recommended height for this size is above 163 cm and your weight should be around 100 to 140 pounds.

Pro XL:

This has a frame size of 20.7 to 21 inches and a wheel size of 22 inches. The estimated height of the rider is 165 cm to 181 cm and the rider should be an adult. The rider should have a weight of around 110 to 140 pounds. 

Pro XXL:

This category is also only for riders above the age of 18 and can hold more than 165 pounds. It has a wheel size of 24 inches and a bike frame size of 21.5 to 22 inches. You should be at least 175 cm tall to ride around with it comfortably. 


This size is not as popular as the other ones and not widely available. It has a frame size of 22 inches, larger than all types, and a wheel size of more than 20 inches. You should be at least 175 cm tall to ride it. 


This is a special type that has a good balance and is easy to ride. They have a wheel size of 24 inches and a bike frame size of 21.5 to 21.75 inches. This is suited for riders above the age of 18. It is also convenient if you are 5 feet and 10 inches in height or above. Just like Pro XXL, It can hold more than 165 pounds. 

BMX bike size chart

The wheel size in BMX bikes tends to be smaller than mountain bikes. They are typically 20 inches but can be 24 inches. 

The 24 inches ones are known as Cruisers which are used by tall and professional riders. Small wheel sizes such as 15, 16, 17, and 18 are available but they are mostly for children. 

The top tube, also known as the bike frame size, is the most important measurement when you pick your BMX bike. It connects the front of the bike with the seat post tube. This can be around 12 to 22 inches. 

Size NameBike Frame SizeWheel SizeStem LengthBar RiseBar WidthCrank Length
Micro Mini15 to 16 inches16 inches25 mm to 35 mm2 to 2.5 inches20 to 22.5 inches145 mm to 155 mm
Mini16 to 17 inches18 inches30 mm to 40 mm2 to 3.5 inches21 to 23.5 inches155 mm to 165 mm
Junior17 to 18.5 inches20 inches40 mm to 45 mm3 to 5 inches23 to 25 inches160 mm to 175 mm
Expert18.5 to 19.5 inches20 inches43 mm to 48 mm5 to 7 inches25.5 to 27 inches170 mm to 175 mm
Pro20 to 20.5 inches20 inches50 mm to 55 mm6 to 8 inches27 to 28 inches175 mm to 180 mm
Pro XL20.7 to 21 inches22 inches50 mm to 55 mm8 inches and over28 inches and over180 mm to 190 mm
Pro XXL21.5 to 22 inches24 inches52 mm to 60 mm8 inches and over28 inches and over180 mm and over

What BMX bike size should I get? 

The main factor that decides which size BMX bike is right for you is your height. The taller you are, the larger the frame and wheel size will be. The weight and the type of rider you are also plays a role. Bigger sizes are usually for riders who ride on the streets or ride professionally. 

You should be comfortable too so it’s better to try it on first before purchasing a BMX bike. 

Another thing that you should consider is the location. If you’re riding in places such as parks then you don’t require big sizes. For pulling out stunts, a size above 20 inches is recommended

What size BMX bikes do adults use?

Adults use BMX bikes that have a top tube of around 20.5 inches to 22 inches in length. This falls in the Pro-size bike category. Riders who are below the height of 163 cm go for BMX bike sizes which are less than 20 inches. These are Micro Mini, Mini, and Junior. 

Is a 20 BMX too small? 

Not at all. This is the standard frame size as well as the wheel size. So it’s not too small. This will be convenient for you if you have a height of at least 163 cm. It can also hold a body weight of 130 pounds. 

However, this is more for starter-level riders and not meant for professional riding. If you’re looking for something that can withhold more pressure, go for 20.5 or a few sizes larger. 

Frequently asked questions

What is the standard BMX size? 

The standard BMX frame size is 20 inches and the standard BMX wheel size is 20 inches as well. Most BMX bikes come in this size. They fall into the BMX Expert category. 

Both can be used by adults and children. It is the standard size but for professional riding, you might need larger sizes. 

What age is an 18 inch BMX bike for? 

This BMX bike size is most suitable for children under the age of 12. But they should be at least 7 years old. Smaller sizes are available for kids from ages 5-8. This BMX frame size is called ‘Junior’. The height range for this bike is 137 cm to 149 cm. 

What age is a 20 inch BMX bike for? 

Since this is the standard frame and wheel size, this can be used by both adults and children. However, they should be at least 8 years old. The rider should have a height between 163 cm to 181 cm. 

What age is a 26 inch BMX bike for? 

This is mainly used by adults but teenagers over the age of 15 can use this too. They should be at least 5’10 in height. These are also used by professional riders in BMX races! 

Do BMX bikes come in 24 inches? 

Yes. They are known as Cruisers and might not be available in all stores. They can hold more than 165 pounds. Riders who pick Cruisers typically have a height over 175 cm. 

It will be useful to note that cheaper bikes are heavier as they are made with steel instead of alloy. The expensive ones are made with alloy and aluminum. 

Always make sure whichever BMX bike you purchase is a correct fit for you. Your rear should be 1 to 2 inches above the seat when you are standing. Prioritize your comfort over style. 

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