Calculate children's bike size - inches, age, height

A bike that is too small or too large is particularly unsafe for children. But how can you find the right size? Why is information given in inches and not centimeters – and how can this be converted? And at what height should the saddle and handlebar be adjusted? The children’s bike size calculator provides answers.

Calculate the correct children’s bike size

While the bike size for adults is determined by the size of the frame, the diameter of the rim is important for children’s bikes. Confusing: The size is given in inches, not centimeters. But the height of the saddle must also be right: Children must be able to stand safely on the floor with both feet when they are on the bike.

Switching from other vehicles to bicycles is easy

Children learn to ride a bicycle more easily if they have done so beforehand experience have collected with other children’s vehicles. A balance bike, the Kettcar or tricycle each have their own advantages and make the switch easier. These vehicles are already training the balance.

What is the correct bike size??

There are two methods to determine the correct bike size: by height or stride.

The easiest way to determine body height is with a ruler or tape measure. To do this, place your child barefoot with his back against the wall. Make sure your child is standing upright. Carefully make a pencil mark on the wall. Now measure from the marking to the floor: you now know the exact size of your child.

Bicycle size, depending on the size of your child

Height in cm	Bike size in inches	Saddle height in CM
98	10 – 12 inches	42
104	12-14 inches	47
110	12-16 inches	52
116	14-18 inches	55
122	16-20 inches	59
128	18-20 inches	64
134	18-20 inches	67
140	20-24 inches	72
146	24 inches	75
152	24-26 inches	78
158	24-26 inches	81
164	26 inch	83
170	26 inch	86

Alternatively: bike size according to stride length

As an alternative to body size, the correct bike size can also be determined using the stride length of yours.

To determine the stride length, place your child with his back against a wall. Your child should clamp a book or a ruler in the crotch. The stride length corresponds to the distance of this object from the ground. You measure this distance with a tape measure or a ruler.

The size of the wheel depends on the stride length

Stride length in CM	Bike size in inches
40	10 – 12 inches
44	12-14 inches
48	12-16 inches
51	14-18 inches
55	16-20 inches
59	18-20 inches
62	18-20 inches
66	20-24 inches
69	24 inches
72	24-26 inches
75	24-26 inches
77	26 inch
80	26 inch

Pay attention to the rim diameter and the saddle height

The first Children’s bikes can be given to your child from a stride length of 40 cm. A balance bike offers more safety for smaller children.

The stride length is important because it determines the height of the saddle. Children must always be able to safely reach the ground with both feet when cycling, even when their bottom is on the saddle. Because the saddle is height adjustable, most children can use the bike for a few years.

Bicycle size by age

Age in years	Bike size in inches
approx. 2-3	10 – 12 inches
approx. 3-4	12-14 inches
approx. 4 – 5	12-16 inches
approx. 5 – 6	14-18 inches
approx. 6 – 7	16-20 inches
approx. 7-8	18-20 inches
approx. 8 – 9	18-20 inches
approx. 9-10	20-24 inches
approx. 10 – 11	24 inches
about 11 – 12	24-26 inches
about 12 – 13	24-26 inches
approx. 13-14	26 inch
Older than 14	26 inch

12 inch wheels

Bicycles with 12-inch wheels are the smallest bicycles on the market. Your child should be 98 cm or taller and have a stride length of at least 40 cm. 12-inch children’s bikes are usually equipped with training wheels.

14 inch wheels

The children’s bike with 14 inches is aimed at children with a height of 104 cm to 109 cm, the stride length of the child should be around 44 cm. Because these bikes have a saddle with a height of 47 cm. The wheels are available with and without training wheels.

16 inch wheels

If your child has a height of 110 cm or more, a 16-inch bike may be suitable, but sometimes a 14-inch bike is sufficient. The saddle on these bikes is at a height of 52 cm, the stride length of your child should be at least 48 cm. The handlebars and stem of these children’s bikes are mostly padded so that children do not get injured in the event of a fall.

18 inch wheels

From a height of at least 116 cm, 18-inch wheels can be suitable. However, it often does also a 16-inch or even a 14-inch with a correspondingly higher saddle and handlebar. With 18-inch bikes, the saddle is 55 centimeters high and the stride length is at least 51 centimeters. 18-inch bikes are the largest children’s bikes. Everything about it is already called a youth bike.

Only a few of these wheels offer the possibility of mounting support wheels. Up to this height of 18 inches, almost all children’s bikes still have a deep entry. From now on, different frame shapes are available, some with a high entry. The deep entry ensures more safety when getting on and off.

20 inch wheels

From a height of 122 cm and a stride length of around 55 cm, children can get on a 20-inch bike. The saddle height here is 59 cm and the handlebars and stem are often no longer padded.

However, there are now many different types of bicycles to choose from. 20 inch bikes are available as trekking bikes, mountain bikes or fat bikes, city bikes or dirt bikes.

Most bikes in this size are equipped with hub or chain gear shifting, the equipment corresponds to that of a bike for adults.

Depending on the type of bike, suspension forks and lights, chain guards and mudguards are just as available as the luggage rack.

24 inch wheels

24-inch bicycles are aimed at children and adolescents with a height of at least 140 cm. The stride length of the young people is now around 66 cm, so that the youth bikes, which almost look like a bike for adults, no longer look childish.

Mountain bikes and city bikes, but also racing bikes and fat bikes as well as trekking bikes are popular with children. The frame shapes are correspondingly different. Chain or hub gears are a matter of course with this bike size.

Road traffic and security

Children’s bicycles are included in the road traffic regulations as so-called "special means of transportation". You have to follow the same rules as pedestrians.

Children should ride their bikes on the sidewalk until they are eight years old. And if the bike is moved outside of private property (i.e. on public sidewalks), it must be safe to drive.

You need a complete lighting system, a bell and a separate brake for each wheel. Reflectors are required for spokes and rims, and the pedals must be equipped with yellow reflectors. The rear light and headlights in red are mandatory for the rear of the wheel, and the front lights and headlights must be in white.

Summary

In order for your child to ride safely on the bike, the bike must be the correct size. Your child must be able to stand firmly on the floor with both feet when it is sitting on the saddle with its bottom. Children’s bikes are available in sizes from 12 inches to 18 inches; larger bikes are called youth bikes.

The correct children’s bike size can be calculated based on the size of the child and the stride length.
Children’s bikes from 12 inches to 16 inches are mostly play bikes and not safe to drive.
Children’s and youth bikes from 18 inches are usually equipped like bikes for adults.
If children ride on sidewalks and in public parks, the bike must be safe to drive.