How to Measure a Kids Bike

Estimated reading time: 7 minutes

Bike riding is an incredibly healthy pastime for young children. It can help your kid develop the necessary coordination skills and improve their cardiovascular health.

However, before your little one gets on their first bike and pedals out into the world, it is crucial that you, the parent or guardian, understand how to measure your kid’s bike so that it suits their strength, size and age.

Kids bikes come in all shapes and sizes, so it can be confusing to know which size is right!  In this guide, we’ll look at how to measure kids bike to fit your child perfectly. 

Difficulties with measuring a kids bike

Although most bicycles for kids come with an age and size chart, this is not always suitable as kids grow and mature at different rates.

Kids of the same age can be vastly different in height and weight and have different leg lengths than what is considered average by the charts.

Brands offer different size charts, so make sure you check these before purchasing a bicycle. One size for a particular brand may report being ideal for your kid’s age, while another brand might say something different. 

It is always best to measure the pedal bike yourself to find the perfect size.

About kids’ bike sizes

Similar to adult bicycles, kids bikes come in a variety of sizes. The sizing is typically based on the size of the wheel and includes: 

• 12 inch bikes
• 14 inch bikes
• 16 inch bikes
• 18 inch bikes
• 20 inch bikes
• 24 inch bikes
• 26 inch bikes

The wheel size is the diameter of the tyre, but generally, the bigger the bike, the bigger the tyre. However, using wheel size to measure the bike isn’t the only method to get an accurate size, as we’ll explore.

How to measure kids bicycle sizes

Bike size by wheel size

As we briefly mentioned, measuring a bike by wheel size is not the only optimal method for measuring your child’s bike size. 

A bike sizing chart uses the wheel size to accompany a child’s height. However, if you have ever used this method, you may have come to the shop only to realise that the bike is very ill-fitting, despite what the wheel size and charts indicate.

This problem arises because the bike’s size does not depend only on the wheel’s size. The design and geometry of the childrens bike frame also play a role, which is why one brand can have an 18 inch bike that fits different aged children.

Bike size by inseam

The best way to measure a bike for kids is to use their inseam length. The inseam is measured on the inside leg, from the crotch to the ground. It is best to take this measurement while your child is wearing shoes.

You then use this measurement and compare it to the seat height of the bike you are interested in. Using this measurement, your child can reach the ground comfortably and pedal without difficulty as the seat will be the right height.

Kid’s age, height and weight

Kids grow at different rates. Therefore, you should consider your child’s height, age and weight. A larger child will naturally require a larger bike, for example.

Kid’s bike size chart

Below is an approximate chart using inseam length, wheel diameter, and kids’ age range to help you find the right bike:

12″ bike wheel size

• Approximate inseam: 15″ – 18″
• Approximate height: 36″ – 39″
• Approximate age: 2 – 3 years

12″ bike wheel size

• Approximate inseam: 15″ – 20″
• Approximate height: 37″ – 44″
• Approximate age: 2 – 4 years

16″ bike wheel size

• Approximate inseam: 16″ – 22″
• Approximate height: 41″ – 48″
• Approximate age: 4 – 6 years

20″ bike wheel size

• Approximate inseam: 19″ – 25″
• Approximate height: 45″ – 54″
• Approximate age: 5 – 8 years

24″ bike wheel size

• Approximate inseam: 23″ – 28″
• Approximate height: 54″ – 59″
• Approximate age: 8 – 11 years

26″ bike wheel size

• Approximate inseam: 25″+
• Approximate height: 56″+
• Approximate age: 10+ years

Different children’s bike types by age

Here are some of the most popular types of bikes best suited for different ages to help you find a suitable bike size for your little one.

Balance bikes (2 – 4 years)

Kids balance bikes are perfect for toddlers between the ages of 2 to 4 years old. These are the ideal first bike, as they help kids learn how to balance and steer before adding the pedalling aspect.

Most balance bikes have 12″ wheels and do not have pedals, meaning kids have to propel themselves forward with their feet. Often these bikes don’t have brakes either.

For more information, read our guide on the benefits of balance bikes for kids.

Small wheelers (3 – 5 years)

A small wheeler bike is the perfect first pedal bike once your child has outgrown their balance bike. These bicycles have some basic bike features, like brakes and pedals, but still have wheels measuring around 12″ to 14″.

Our Kids Huffy Star Wars 12”  Bike is a perfect option in the smallest child’s bike size for your budding cyclist.

Middle wheelers (4 – 6 years old)

Middle wheelers are children’s bikes with 16″ wheels. This bigger bike has a larger frame size that supports kids between the ages of 4 and 6 years old.

Considered a big child’s bike, middle wheelers have higher seat heights, making them great for longer rides outside.

Kids of this age absolutely adore the Huffy Pro Thunder 16” Bike! These pedal bikes can go fast, so make sure your child can handle a bike of this size before unleashing them into the road.

Large wheelers (5 – 9 years)

Large wheelers have wheels sized 20″ and up. These bikes are great for older kids that are around the age of 5 to 9 years old.

These kids bikes have gears, hand brakes, suspension, and all the other features you will find in a typical adult bike.

This is typically where specialisation begins, as road bikes and mountain bikes are in this size class.

BMX bikes (5 years +)

BMX bikes are great for outdoor adventurers. A BMX bike can go off-road and survive mud, dirt, jumps and more.

These bikes typically have a wheel diameter of 20 inches and are usually ridden by older kids, although kids as young as 5 years old can master these tough rides.

24 inch bikes (7 years +)

These are the largest kids bikes you can find and are considered transition bikes – whereby your kid is transitioning to an adult bicycle.

BMX bikes, road bikes, mountain bikes and cruisers are all available in this size, so you need to consider what your kid will use the bike for before making a purchase.

FAQs about kids bike measurements

Should I buy a larger bike that my kid will grow into?

No, it is not a good idea to buy a bike that is too big. If your kid cannot reach the handlebars or pedals, they will not be able to control or steer the bike, which could lead to accidents. Instead, get a bike that has been properly measured for your child’s height and age.

At what age should I get a bike for my child?

Kids can start riding balance bikes from as early as 18 months. By age 5, most kids will be able to ride a pedal bike. Little ones can also enjoy toddler ride on cars if they haven’t mastered balancing on two wheels yet!

Are balance bikes or training wheels better?

Balance bikes teach necessary cycling skills, like leaning into the turn to steer or how to balance. Training wheels do have their place, however, as they help develop coordination and pedalling skills. Neither is better than the other, and both are very useful.

Find the perfect kids bike with Electric Ride On Cars

At Electric Ride On Cars, we provide a range of kid’s bikes to suit your child and their interests. Why not take a look at our electric dirt bikes for kids? Or for something cooler, kids electric motorbikes are great for riding in style. 
If your little one isn’t as comfortable on two wheels, take a look at our range of kids electric cars for more options.