What size bike for my child? Kids' bike sizes by height, from the makers' charts
Kids' bikes are sized by wheel, and the right wheel depends on your child's height, not their age. Two kids the same age can need different bikes. I'm a beginner learning bike repair on my own $258 Walmart bike, but RideLoadout covers kids' bikes too, so I dug into the makers' charts to understand how they're sized. Here's what I found.
What size bike for my child's height?
These ranges come from the makers' charts for the kids' bikes in the app's guide. They overlap, so a child near the top of one size may also fit the next.
| Wheel size | Child's height | Usual ages |
|---|---|---|
| 12″ | about 2′10″ – 3′4″ (85–100 cm) | 2–4 |
| 16″ | about 3′4″ – 4′0″ (102–122 cm) | 4–6 |
| 20″ | about 3′9″ – 4′7″ (115–140 cm) | 6–9 |
| 24″ | about 4′2″ – 4′11″ (127–150 cm) | 8–12 |
| 26″ or small adult | about 4′10″ and up (147 cm and up) | 11 and up |
The kids' bike size guide lists the exact range for each bike, and the app's kids' bike finder matches bikes to your child's height and inseam.
Should I buy a bigger bike so they can grow into it?
Everything I read says no. A bike that's too big is hard to control, hard to stop and scary, and kids ride it less. The advice is to buy the size that fits now. Kids' bikes resell well, especially the lighter bike-shop brands, so you get some money back when they move up.
How do I check if a kids' bike fits?
These are the checks I found:
- New riders: with the seat all the way down, both feet should be flat on the ground.
- Confident riders: tiptoes on both sides is fine.
- Hands: they should reach the brake levers easily. Many good kids' bikes have levers that adjust in for small hands.
Why does the bike's weight matter so much?
A kids' bike is a big share of a small rider's weight. A bike under about 30% of your child's weight feels easy to pedal, steer and pick up. Over about 40% feels heavy. Many cheap 16″ bikes weigh around 20 lb (9 kg), which is a lot for a 40 lb child.
Hand brakes or a coaster brake?
From what I read, hand brakes are easier to learn on for most kids, as long as the levers fit small hands. A coaster brake (pedal backward to stop) can surprise kids who backpedal to get their pedal in place, and it stops working if the chain comes off. Many bikes have both, which is fine.
Do kids need gears?
Not usually. Single speed is simplest for 16″ and most 20″ bikes. Gears start to help on 24″ bikes and in hilly areas. I'm writing up every repair as I learn it, in order: see my journey.