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:
- Height: Have your child stand against a wall without shoes on and measure their height from the floor to the top of their head.
- 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 Size | Inseam | Height |
| 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
| Age | Height | Inseam | Suggested Boy Bike Size |
| 2 Years | 34.2″ (86.8 cm) | 15″ | 12″ wheels |
| 3 Years | 37.5″ (95.2 cm) | 16.5″ | 12″ or 14″ wheels |
| 4 Years | 40.3″ (102.3 cm) | 17.7″ | 14″ wheels |
| 5 Years | 43.0″ (109.2 cm) | 18.9″ | 16″ wheels |
| 6 Years | 45.5″ (115.5 cm) | 20″ | 16″ or 18″ wheels |
| 7 Years | 48.0″ (121.9 cm) | 21.1″ | 18″ or 20″ wheels |
| 8 Years | 50.4″ (128 cm) | 22.2″ | 20″ wheels |
| 9 Years | 52.5″ (133.3 cm) | 23.1″ | 24″ wheels |
| 10 Years | 54.5″ (138.4 cm) | 24″ | 24″ wheels |
| 11 Years | 56.5″ (143.5 cm) | 24.9″ | 26″ wheels |
| 12 Years | 58.7″ (149.1 cm) | 25.8″ | 26″ wheels |
| 13 Years | 61.5″ (156.2 cm) | 27.1″ | 26″ wheels |
| 14 Years | 64.5″ (163.8 cm) | 28.4″ | 26″ wheels |
| 15 Years | 67.0″ (170.1 cm) | 29.5″ | 27.5″ wheels |
| 16 Years | 68.3″ (173.4 cm) | 30.1″ | 27.5″ wheels |
| 17 Years | 69.0″ (175.2 cm) | 30.4″ | 27.5″ wheels |
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:
| Age | Height | Inseam | Suggested Girl Bike Size |
| 2 Years | 33.7″ (85.5 cm) | 14.8″ | 12″ wheels |
| 3 Years | 37.0″ (94 cm) | 16.3″ | 12″ wheels |
| 4 Years | 39.5″ (100.3 cm) | 17.4″ | 12″ or 14″ wheels |
| 5 Years | 42.5″ (107.9 cm) | 18.7″ | 16″ wheels |
| 6 Years | 45.5″ (115.5 cm) | 20″ | 16″ or 18″ wheels |
| 7 Years | 47.7″ (121.1 cm) | 21″ | 18″ or 20″ wheels |
| 8 Years | 50.5″ (128.2 cm) | 22.2″ | 20″ wheels |
| 9 Years | 52.5″ (133.3 cm) | 23.1″ | 24″ wheels |
| 10 Years | 54.5″ (138.4 cm) | 24″ | 24″ wheels |
| 11 Years | 56.7″ (144 cm) | 24.9″ | 26″ wheels |
| 12 Years | 59.0″ (149.8 cm) | 26″ | 26″ wheels |
| 13 Years | 61.7″ (156.7 cm) | 27.1″ | 26″ wheels |
| 14 Years | 62.5″ (158.7 cm) | 27.5″ | 26″ wheels |
| 15 Years | 62.9″ (159.7 cm) | 27.7″ | 26″ wheels |
| 16 Years | 64.0″ (162.5 cm) | 28.2″ | 26″ wheels |
| 17 Years | 64.0″ (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.
| Height | Inseam | Suggested 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 |
Conclusion:
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.