Kids Bike Size Guide (+Boys & Girls Sizing Charts)

Choosing the proper bike size for your kid is one of the most crucial things you as a parent can do to ensure their safety and enjoyment while biking. It can be uncomfortable, challenging, and even dangerous to ride a bike that is too big or too small. This manual will explain the various bike sizes available, take you through the process of measuring your child’s bike size, and provide advice on how to find the bike that will suit your child the best.

How to Measure Kids Bike Size

Before buying a bike for your child, it’s essential to measure their height and inseam to determine the appropriate size. Here’s how to do it:

  1. Height: Have your child stand against a wall without shoes on and measure their height from the floor to the top of their head.
  2. Inseam: Have your child stand with their back against a wall and their feet shoulder-width apart. Place a book between their legs, with the spine against their crotch. Measure the distance from the floor to the top of the book.

Once you have both measurements, you can use the charts below to find the right bike size for your child based on their age, height, and inseam. 

Kids Bike Size By Wheel Size

Different from adult bikes, kids bikes are sized by wheel size instead of “frame size”. 12”, 14”, 16”, 18”, 20” and 24” are the standard wheel sizes for kids. Here’s a chart of recommended bike sizes for based on height, and inseam: 

Wheel SizeInseamHeight
12″15″ – 18″33 – 39″
14″15″ – 20″37 – 43″
16″16″ – 22″41 – 47″
18″17″ – 23″42 – 49″
20″19″ – 25″44 – 53″
24″23″ – 28″50″ – 59″
26″25″ – 30″56″ -67”

Kids Bike Size by Age

What size bike for a 5 year old? Or what size bike for a 6 year old girl? You may want to get an estimated bike size directly based on your child’s age. We have summarized kids bike data from top manufactures and simplified it into the two charts below.

Here’s a chart of recommended bike sizes for boys based on age, with his estimated height and inseam. And you can find the chart for girls below.

Boys Bike Size by Age Chart

AgeHeightInseamSuggested Boy Bike Size
2 Years34.2″ (86.8 cm)15″12″ wheels
3 Years37.5″ (95.2 cm)16.5″12″ or 14″ wheels
4 Years40.3″ (102.3 cm)17.7″14″ wheels
5 Years43.0″ (109.2 cm)18.9″16″ wheels
6 Years45.5″ (115.5 cm)20″16″ or 18″ wheels
7 Years48.0″ (121.9 cm)21.1″18″ or 20″ wheels
8 Years50.4″ (128 cm)22.2″20″ wheels
9 Years52.5″ (133.3 cm)23.1″24″ wheels
10 Years54.5″ (138.4 cm)24″24″ wheels
11 Years56.5″ (143.5 cm)24.9″26″ wheels
12 Years58.7″ (149.1 cm)25.8″26″ wheels
13 Years61.5″ (156.2 cm)27.1″26″ wheels
14 Years64.5″ (163.8 cm)28.4″26″ wheels
15 Years67.0″ (170.1 cm)29.5″27.5″ wheels
16 Years68.3″ (173.4 cm)30.1″27.5″ wheels
17 Years69.0″ (175.2 cm)30.4″27.5″ wheels
The Height and Inseam data is based on Disabled World.

Girls Bike Size by Age Charts

Girls’ bike sizes may differ from boys’ bike sizes due to differences in height and inseam measurements. Here’s a chart of recommended bike sizes for girls:

AgeHeightInseamSuggested Girl Bike Size
2 Years33.7″ (85.5 cm)14.8″12″ wheels
3 Years37.0″ (94 cm)16.3″12″ wheels
4 Years39.5″ (100.3 cm)17.4″12″ or 14″ wheels
5 Years42.5″ (107.9 cm)18.7″16″ wheels
6 Years45.5″ (115.5 cm)20″16″ or 18″ wheels
7 Years47.7″ (121.1 cm)21″18″ or 20″ wheels
8 Years50.5″ (128.2 cm)22.2″20″ wheels
9 Years52.5″ (133.3 cm)23.1″24″ wheels
10 Years54.5″ (138.4 cm)24″24″ wheels
11 Years56.7″ (144 cm)24.9″26″ wheels
12 Years59.0″ (149.8 cm)26″26″ wheels
13 Years61.7″ (156.7 cm)27.1″26″ wheels
14 Years62.5″ (158.7 cm)27.5″26″ wheels
15 Years62.9″ (159.7 cm)27.7″26″ wheels
16 Years64.0″ (162.5 cm)28.2″26″ wheels
17 Years64.0″ (162.5 cm)28.2″26″ wheels

Kids (Boy And Girl) Bike Size By Height

If you want to estimate the bike size by height roughly, here is a detailed table of suggested size by height. 

HeightInseamSuggested Bike Size
38″16.7″12″ wheels
39″17.2″12″ wheels
40″17.6″14″ wheels
41″18″14″ wheels
42″18.5″14″ wheels
43″18.9″16″ wheels
44″19.4″16″ or 18″ wheels
45″19.8″16″ or 18″ wheels
46″20.2″18″ wheels
47″20.7″18″ wheels
48″21.1″18″ wheels
49″21.6″20″ wheels
50″22″20″ wheels
51″22.4″20″ wheels
52″22.9″20″ wheels
53″23.3″24″ wheels
54″23.8″24″ wheels
55″24.2″24″ wheels
56″24.6″24″ wheels
57″25.1″26″ wheels
58″25.5″26″ wheels
59″26″26″ wheels
60″26.4″26″ wheels


In conclusion, selecting the right bike size for your child is a crucial step in ensuring their safety and enjoyment while cycling. Accurately measuring your child’s height and inseam, and referring to the recommended charts, can help you choose the perfect size bike.

It’s worth noting that while standard bike sizes can be a useful guide, each child is unique and may require some adjustments to find the most comfortable fit. By testing out different options and making modifications when necessary, you can help your child build confidence and enjoy all the fun and benefits of cycling. 

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