Kids Bike Size Calculator
Enter your child’s age, height or inside leg to find the right bike wheel size, from balance bikes to 26-inch bikes.
What size bike for my child?
Most kids ride a balance bike at 18 months to 3, a 12-inch bike at 2 to 4, 14-inch at 3 to 5, 16-inch at 4 to 7, 20-inch at 6 to 9, 24-inch at 8 to 12 and 26-inch from about 11. Height and inside leg are more accurate than age.
How to use the kids bike size calculator
Choose your child’s age for a quick estimate.
Measure in shoes against a wall.
Put a book between their legs like a seat and measure to the floor.
Get the wheel size, brake type and a riding tip.
Kids bike size chart
| Wheel size | Usual age | Height | Inside leg |
|---|---|---|---|
| Balance bike | 18 months to 3 | 31 to 38 in | 12 to 16 in |
| 12 in | 2 to 4 | 34 to 40 in | 14 to 17 in |
| 14 in | 3 to 5 | 37 to 44 in | 16 to 20 in |
| 16 in | 4 to 7 | 41 to 48 in | 18 to 22 in |
| 20 in | 6 to 9 | 45 to 54 in | 21 to 25 in |
| 24 in | 8 to 12 | 50 to 60 in | 24 to 28 in |
| 26 in | 11 and up | 56 in and up | 26 in and up |
Charts overlap because brands vary. When in doubt, choose the smaller size for a beginner and the larger size for a confident rider.
How a kids bike should fit
- Seated, your child can touch the ground with the balls of both feet.
- Standing over the frame, there is a little space between them and the top tube.
- They can reach the handlebars with slightly bent arms.
- Knees do not hit the handlebars when pedaling.
Balance bike or training wheels?
Balance bikes teach balance and steering first, and many kids skip training wheels later. Training wheels still work well, especially for older beginners. See our best kids bikes for picks of both.
Brakes by size
Small bikes (12 to 16 in) usually have coaster brakes that work by pedaling backward. From 20 in, many bikes add hand brakes. Practise braking early so stopping feels natural.
Safety first
- Always wear a helmet that fits snugly and sits level.
- Ride in safe places like parks and quiet paths.
- Check tire pressure and brakes before each ride.
- Add lights and a bell for older kids.
RoyalBaby Freestyle Kids Bike
You need this if: you want a sturdy, well-reviewed first pedal bike for ages 3 to 10.
It is one of the best-selling kids bikes on Amazon, with more than 15,000 ratings, and comes about 95% assembled in several sizes.
More choices: best kids bikes by age. We earn a commission when you buy through our links, at no extra cost to you.
Frequently asked questions
What size bike for a 5 year old?
Usually a 14 or 16-inch bike, depending on height.
What size bike for a 7 year old?
Usually a 16 or 20-inch bike.
What size bike for a 10 year old?
Usually a 20 or 24-inch bike.
Is height or age better for bike size?
Height and inside leg are more accurate than age.
Should I buy a bigger bike to grow into?
No. A bike that is too big is hard to control and unsafe.
When should my child move to a bigger bike?
When their knees come close to the handlebars or they can sit with both feet flat on the ground even with the seat raised.
