Kids’ Bike Size Chart: How to Pick Bike Size for a Kid

We explain the basics of kids' bike sizes and guide you on how to measure your child correctly to get a perfect size.
John Watson
John Watson
John is an experienced cycling enthusiast and a great asset when it comes to writing skills. He's a Bachelor of Arts and a talented journalist. John is in charge of our blog read more
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Jessica Kingston
Jessica Kingston
Expert Consultant
Jessica is our expert consultant on all things connected to biking - gear, technique, you name it. Being a pro cyclist in the past, she knows exactly how things work in and read more
Last updated: September 08, 2023
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A children’s bike must meet numerous requirements: it must be safe, withstand shocks, and the cycle must be the most suitable size. However, determining the correct bike size for children can be tricky. For this, you can use the kids’ bike size chart by height which will help you measure the height of your child correctly to get the right bike. Some simple secrets will help you get the best present for your little one.

Why Is It Important to Pick the Right Bike Size for Your Kid?

When purchasing a bike for a child, it’s essential to make sure you’re buying the right size. Dangerous situations can arise if the bike is too big. Children grow up very quickly. That’s why it’s essential to check that your child’s bike is adjusted correctly regularly. Make sure the handlebar and saddle are adjusted to the correct height. The legs should not be completely straight when pedaling, and the feet should lightly touch the ground.

According to LIV Global Trusted Source How to Buy a Bike for Your Kid | Liv Cycling Official site Unlike bicycles for adults, children’s bikes are not sized based on the frame height or length. Instead, they are offered in sizes based on wheel size. , unlike adult bikes, which are the same size as the frame, children’s bikes are sized by wheel size.

The size of children’s bikes, like bikes for adults, is determined by the cyclist’s height, not by age. The height of kids of the same age can vary quite a lot.

With the help of a specialized kids’ bike size chart by height and inseam, you can figure out the most suitable bicycle size for your kid.

How Are Kid’s Bikes Measured?

Numerous parents want to know how are kids’ bikes measured. With the help of charts, you can correctly measure the dimensions needed for the perfect bike. When buying a bicycle in a shop, you will most likely be offered assistance in choosing the right frame for your kid’s height. But you will feel much more confident as a parent if you know all the subtleties of this issue.

Kids' Bike Size Chart: How to Pick Bike Size for a Kid

When you want to know how to measure and pick a bike for a kid, remember that almost all bike frames come in a variety of sizes. And each manufacturer classifies them differently. Each bike model has at least 3 to 4 dimensions and different markings. Frames are marked by height in form of numbers and characters. The defining parameter for the frame of any bicycle is the height of the seat tube. It is measured from the center of the bottom bracket to the end of the tube. It can be specified in either inches or centimeters.

Kids’ Bike Measurements You’ll Need to Take

To determine the right children’s bikes sizes, it is worth arming yourself with a tape measure and measuring the height of the child and the length of the leg along the inner surface. So you will narrow down the search for a suitable model from a large assortment of bikes in all colors and sizes presented in the store.

According to REI, before the first ride, you need to check the bike for the rider’s height and adjust the position of the saddle and handlebars. Ask the child to stand above the bike so that the frame is between the legs, while the distance from the frame to the groin should be at least 7 cm. Ensure that the child is not standing on his toes but with a whole foot. Such a gap is needed so that the baby is not injured when jumping off the pedals. Then, put him in the saddle, check that the fully extended leg reaches the pedal in the lower position and that the knees do not touch the handlebars when pedaling. The harness and handlebars of most children’s bikes can be adjusted in height for optimal seating.

Bike Size Chart

If you are wondering what size bike you need for your child, this kids bicycle size chart will help you follow the most typical measurements of a child’s height to pick the right bike for you:

Bike Wheel Size Approx. Age Kid’s Height Kid’s Inseam
12” 2-3 2’10”-3’4” 14-17” 35-42 cm
14” 3-4 3’1”-3’7” 16-20” 40-50 cm
16” 4-5 3’7”-4’0” 18-22” 45-55 cm
18” 5-6 3’9”-4’3” 20-24” 50-60 cm
20” 5-8 4’0”-4’5” 22-25” 55-63 cm
24” 7-11 4’5”-4’9” 24-28” 60-72 cm

Measuring Bikes for Boys vs. Girls: Is There a Difference?

Bicycles for boys and girls differ only in a few details. Bicycles designed for even the most petite boys usually have a metal stem, while bikes designed for girls do not. The higher crossbar on the boy’s bike increases the stability of the bike frame.

Even though stepped frames are not as strong, they provide ease of mounting and dismounting.

Nevertheless, now there is a trend that all bicycles for children are more unified. Some women’s bikes have slightly smaller grips, brake levers, and tires. Yet, bicycles are more or less the same for children at an early age, so there is not much difference in how to calculate the correct measurements for boys’ and girls’ bike sizes and create a separate size chart. It is worth looking only at the physiological characteristics of your child.

What Else to Look For?

To purchase the perfect bike for your little one, here are a few essential points to consider when choosing a bike.

Bike Stand-Over Height

The stand-over height is the height of the top tube of the frame that your kid will sit on when they stand with one foot on each side of the bicycle. It means that a child’s inseam length should be, or at least the same as, the height of the upright.

Easy-to-Reach Handlebars

Kids' Bike Size Chart: How to Pick Bike Size for a Kid

There are unique handlebars and kids’ bike frame size chart to help buyers choose the right size. The handlebar should be selected to make it convenient for the child to hold it in outstretched arms. It is worth focusing on the length of your baby’s arms. Nonetheless, the handlebar is an adjustable part — you can constantly adjust it. Understanding how to raise the handlebars on a kid’s bike can take your child’s comfort to a whole new level.

Seat Height

This element is plastic and metal, with a foam pad and a leather cover. It is worth choosing a seat, focusing on the distance between the pelvis bones. Plastic seats are made mainly for tricycles with a handle. Older children should choose a leather saddle with soft padding, as these riders use the product more intensively. Proper bike fit depends on the height of the bike seat concerning the child’s inseam.

Level of Pedals

Pedals for children’s bicycles are made of either rubber or metal. The second option is preferable. Plastic pedals are an element that is mainly used when equipping children’s bicycles with a handle for the smallest. Consequently, buying models with such pedals is recommended for children under four years old.

The video below goes through all the aspects of choosing the right bike size for a child.

Does the Type of Bike Matter?

Depending on the height and age of the kids, bicycles with different wheel sizes are suitable for them. According to a bike size chart for kids, bicycles with 12-inch wheels are designed for babies up to 3 years old who are just starting their journey in mastering a bicycle; bicycles with 14 and 16-inch wheels are suitable for toddlers from 3 to 5 years old. You can look into the article about the best 16-inch bikes to find numerous wonderful options for your kids; here, you will find the best-evaluated models that can appeal to many young riders.

Not only that but also bicycles with 18 and 20-inch wheels will fit boys and girls from 5 to 9 years old. 24-inch wheels are already a teenage standard (9-12 years old). The kids’ bike wheel size chart will help you figure out the most suitable wheels for your toddler. There are different types of bicycles, all designed for various purposes. Rascal Rides Trusted Source Best Kids Bikes: How To Choose, Reviews, & More! - Rascal Rides Don’t buy a sub-par bike your child (or grandchild)! In this guide we’ll share the best kids bikes and give you tips on how to choose. says there are the most popular types of bikes: balance, with pedals, mountain, hybrid, and BMX ones.

Balance Bikes

Balance bikes are designed for children over 18 months of age. They develop a sense of balance and fine motor skills, do not have pedals and are set in motion by the child’s feet, pushing them off the ground. The easiest way to learn to balance is on such bikes. Moreover, they are the lightest of the children’s bikes. There are balance bikes with wheel diameters from 10 to 20 inches. The wheels can be plastic or made of inflatable rubber. The former is much lighter but only has a good grip on hard or hard-packed surfaces.

Bikes with Pedals and Training Wheels

Kids' Bike Size Chart: How to Pick Bike Size for a Kid

A bike with 12-inch wheels is usually the first pedal bike for a toddler. It is designed for heights between 85 and 105 cm. Since this is often the first bike for a toddler, it is best to opt for a simplified design without components that can complicate the riding experience, such as multiple gears, a lever rear handbrake, or front suspension. The feeling of comfort is crucial for the first bicycle, so make sure the size is accurate and the child is happy with the bike’s look. If you are seeking the best bike for your toddler, you can look into the best 14-inch bikes, in this article you can check out the most astonishing options with detailed information.

Mountain Bikes

When choosing a children’s bike, pay attention to the diameter of the wheels. For children 5-9 years old, their optimal size is 20 inches, and the height of the frame is 12-13 inches. If you look into the article about the best bikes for 5-year-olds, you will discover the top best products which have various characteristics that can meet the needs of each customer.

Shock absorbers smooth out the bumps experienced by the wheels while driving on rough roads. Thus, comfortable conditions are created for the young cyclist.

Therefore, riding a mountain bike in the forest or the countryside is good. It is also suitable for urban needs. If you are looking for bikes of this size, you can discover the best 20-inch mountain bikes for kids article where you can find all the needed information for the purchase. For instance, Dynacraft Magna Front Shock Mountain Bike is one of the best options on the market. It is one of the most durable bikes, with front and rear linear brakes, an 18-speed derailleur, and a padded seat.

Hybrid Bikes

A hybrid is a bicycle that combines attributes of road and mountain models. These models are similar to mountain bikes but more comfortable. The design of such bikes is adapted for driving on paved roads. There are a host of other characteristics which distinguish these bikes. There are a host of other characteristics which distinguish these bikes. They include:

  • V-brakes are widespread sightings on the bikes. Nevertheless, they are not as efficient as hydraulic and mechanical disc brakes. If you are looking to gift your child a good bike, go for one with hydraulic brakes, especially for off-road cycling.
  • You should likewise pay attention to gearing systems in hybrid bikes. They are pretty versatile. The most common types are cassettes and triple chainsets. Nevertheless, it should not come as a surprise that sometimes you will end up with hybrids that feature single-speed and hub gears models.

BMX Bikes

Kids' Bike Size Chart: How to Pick Bike Size for a Kid

The choice of BMX is a purely individual matter. Some like to ride on short frames, some on long ones. The length of the tube depends on the size of these bicycles. The difference between 20.0″ and 21.0″ will only be in the length of the bike, which significantly affects its nimbleness and how easy it will be to do tricks on it. There are the following varieties:

  • BMX flight is for racing.
  • BMX dirt is for ski jumping and performing figures in the air.
  • BMX park is for riding in specially equipped parks with figured flyovers.
  • BMX street is for extreme stunts in the urban landscape and buildings.

Models for off-road racing are light and rigid. Their frame is low and long. The brake is usually rear.

With the information from the best BMX bikes for kids article, it is easier to choose and buy the most comfortable bicycle. Tony Hawk 20″ Jargon Freestyle BMX Bike is one of the most prominent players on the market. It has a solid frame with a luxurious paint job. It has a full chainguard, custom handlebars, front and rear caliper brakes, and a comfortable kickstand.


What size bike should I choose for a 3-year-old?

An average 3-year-old kid is around 3’1”- 3’4” high. A 12” to 14” wheel-sized bike is a perfect option for this group age.

What is the best bike size for a 4-year-old?

A 4-year-old kid is usually around 3’7” high and the best-suited bike for them is the one with a 14” to 16” wheel size.

What size bike to get for a 10-year-old?

A 10-year-old kid is approximately 4’5”-4’9 so we recommend you choose a 24” wheel size bike.

Final Thoughts

A bike ride is interesting for a child of any age, but choosing the right model is a rather difficult task, given the range offered today on the children’s goods market. When opting for the best bicycle, consider not only the kids’ mountain bike size chart but also the opinion of the child because the bike should bring them joy.

A properly selected bike will bring a lot of joy to your child. Riding a bicycle will develop a child’s sense of balance, eye, coordination, endurance and strength. Joint bike rides are perfect for outdoor activities and will help you get to know the world around you better.


How to Buy a Bike for Your Kid | Liv Cycling Official site
Unlike bicycles for adults, children’s bikes are not sized based on the frame height or length. Instead, they are offered in sizes based on wheel size.
Best Kids Bikes: How To Choose, Reviews, & More! - Rascal Rides
Don’t buy a sub-par bike your child (or grandchild)! In this guide we’ll share the best kids bikes and give you tips on how to choose.

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