Kids' Bike Size Guide: Height, Wheels & Fit
The right bike is the one your child can start, steer and stop with confidence. Height and inside-leg length are better starting points than age alone. Wheel size helps you compare options, but the frame shape, saddle height and reach still need to suit the rider.
Measure before choosing
Stand tall, without shoes
Measure your child standing straight against a wall without shoes.
Use a book and a tape measure
For the inside-leg measurement, place a book gently between their legs with its upper edge level, then measure vertically from the floor to that edge. Compare this inseam with the minimum recommended for the exact model.
Write down both measurements. If you are buying a surprise gift, a current height measurement is more useful than choosing a larger bike for the next birthday.
Kids’ bike sizes: a model-specific starting point
The examples below use woom’s published sizing. They show how balance bikes and pedal bikes overlap, and how two bikes with the same wheel size can have different fit requirements. These ranges apply to the named models, rather than every bicycle with those wheels.
Swipe the table to compare all measurements →
| Model | Type / wheels | Rider height | Approximate age | Minimum inseam |
|---|---|---|---|---|
| GO 1 | Balance / 12″ | 82–100 cm | 1½–3½ | Check the fit on the bike |
| GO 1 PLUS | Balance / 14″ | 95–110 cm | 3–4½ | 35.5 cm |
| GO 2 | Pedal / 14″ | 95–110 cm | 3–4½ | 37.5 cm |
| GO 3 | Pedal / 16″ | 105–120 cm | 4–6 | 43.5 cm |
| GO 3 AUTOMAGIC | Pedal / 16″ | 105–120 cm | 4–6 | 43.5 cm |
| GO 4 | Pedal / 20″ | 115–130 cm | 6–8 | 51.5 cm |
| EXPLORE 4 | Pedal / 20″ | 115–130 cm | 6–8 | 56.1 cm |
| EXPLORE 5 | Pedal / 24″ | 125–145 cm | 7–11 | 60 cm |
| EXPLORE 6 | Pedal / 26″ | 140–165 cm | 10–14 | 70 cm |
Select the exact generation as well as the model number: GO 2 and ORIGINAL 2 have their own sizing and specifications. Browse woom bikes, balance bikes or the full kids’ collection to compare current options.
Check the fit on the bike
- Starting and stopping: your child should be able to mount, get moving and stop without struggling to control the bike.
- Saddle position: follow the model’s fit guidance. A balance-bike rider needs confident ground contact; a developing pedal-bike rider’s setup should also suit their experience.
- Reach: shoulders should feel relaxed, with a comfortable bend in the elbows and no need to stretch to steer.
- Braking: check that small hands can reach and operate the levers. Try this while stationary before riding.
- Handling: ask your child to make an easy turn, stop and move the bike by themselves. A bike that is awkward to control is not a good fit simply because the height range looks right.
What if your child is between sizes?
Compare both sizes in person. The smaller option may be easier for a new rider to control, while a confident rider may be comfortable on the next size if the inseam, reach and handling checks all work. Do not choose the larger bike just to make it last longer.
Common sizing questions
Balance bike or pedal bike?
A balance bike lets a child practise steering, balance and stopping without managing pedals at the same time. Moving to a pedal bike depends on both fit and readiness. An older child who is still learning can also need a balance-bike option: age alone does not decide.
Can I choose by age or wheel size alone?
Use them to narrow the search, then check height, inseam and the actual bike. A 20-inch wheel label does not tell you the minimum saddle height or how far the rider must reach.
Arrange a fitting or test ride Explore kids’ bikes
Bring the height and inseam measurements, and confirm the model and size before travelling.
