Kids Bike Size Chart

How to measure a child’s height and inseam

For height, have your child stand upright against a wall. Place a level book on their head, mark the wall and measure from the floor. For inseam, hold the book firmly between their legs like a saddle and measure from the floor to the top edge.

Follow the brand’s footwear instructions. Woom’s US guide and Giant’s STP guide ask for riding shoes when measuring inseam. Use a measured leg length, not a clothing size.

See the illustrated height and inseam measuring guides for the book-and-wall method.

Wheel size is not a frame size

A kids’ bike wheel label describes wheel diameter. It does not tell you saddle height, standover or how far the bars sit from the rider. Guardian’s sizing guide explains why different frames with the same wheel size can fit differently.

Keep the model, version and market with every size comparison. Use the brand’s rider ranges first, then check the actual bike’s adjustment range and controls.

When to size up

Choose a bike your child can control today. Giant advises against buying a bike that is too large for a child to grow into. Overlapping chart ranges give you models to try, without making the larger one the automatic choice.

Our guidance: consider moving up when the current model’s published range no longer fits your child, then check the next model’s height and inseam ranges. Have your child try starting, stopping and reaching the brakes. A birthday alone does not establish fit.

Balance bike vs pedal bike

A balance bike has no pedals. Guardian describes it as a way to learn balance before pedaling. Use the bike’s own sizing and setup guidance; the wheel label alone cannot decide whether a child is ready for pedals.

Prevelo distinguishes learning to pedal from already riding independently. Its recommendations account for experience as well as leg length. Check that guidance when comparing a first pedal bike with a model intended for a confident rider.