Kids bike size
Enter your child's age and move the slider: you see which bike fits when, and for how long — for a child who is just starting and for one who already rides confidently. With the height it gets more precise.
Both feet flat or balls of the feet on the ground
That is all the adjustment a kids bike needs. A child who is just starting has to stand securely when stopping, so both feet flat. A child who already rides confidently manages with the balls of the feet: the saddle sits higher and pedalling gets easier. The makers' own figures lie exactly in this range.
Kids bike sizes by height
All sizes as a table
| Size | confident from | beginner from | up to about | Rough age |
|---|---|---|---|---|
| Balance bike | 85 cm | 85 cm | 100 cm | 2–3½ |
| 14 inch | 91 cm | 97 cm | 110 cm | 3–4½ |
| 16 inch | 101 cm | 107 cm | 120 cm | 4–6 |
| 20 inch | 116 cm | 123 cm | 135 cm | 6–8 |
| 24 inch | 130 cm | 137 cm | 148 cm | 8–11 |
| 26 inch | 140 cm | 147 cm | 165 cm | 10 and up |
A balance bike has only one stage: without pedals the child keeps balance with both feet. 12 and 18 inch bikes with pedals exist too, but rarely — check the lowest saddle height as above.
Why wheel size alone is not enough
The inch figure gives the wheel diameter, not how low the saddle goes. At 16 inch one bike's saddle can go 6 cm lower than another's — that is about 10 cm of height, almost two years of growth. Two children of the same height, by contrast, hardly differ. So look up the model's lowest saddle height: Kubikes and Early Rider list it in their size chart, woom on the product page.
Don't buy one to grow into
A bike one size too big means, for a child who is just starting: 6 to 7 cm of height are missing before both feet stand flat, a good year. Until then the child stops on tiptoe or jumps off. woom and Kubikes explicitly advise against it. If the child already rides confidently and is between two sizes, the bigger one is fine — if the saddle goes low enough.
Mind the weight
Kids bikes weigh from just over 5 to more than 11 kg. For a child of 20 kg, 11 kg is half their own weight — as if an adult of 75 kg rode a 35 kg bike. A light bike is easier to set off on, to steer and to carry up the stairs. Mudguards, rack and lights make a bike practical for every day, but heavier too.
Measure the inseam when it is close
Socks on, back against the wall, a hardback book level between the legs with the light pressure of a saddle. Mark the top edge on the wall and measure straight down to the floor. To be honest: this measurement is easily a few centimetres off too, about as far as the estimate from height. Sitting on the bike you want to buy is the surest test.
And your own bike?
Saddle height calculator Frame size calculator
Where the numbers come from: the size charts of woom, Kubikes, Puky, Early Rider (retrieved October 14, 2026) and measurements of 3,487 children (Snyder, Schneider, Owings 1977, for the US Consumer Product Safety Commission).
This is a guide from measurements and makers' figures, not a substitute for sitting on the bike. This page stores nothing — the height lives only in the address.