Kids’ bikes are measured in wheel inches but chosen by the child’s height, not age — two four-year-olds can differ by 15 cm. The calculator above turns height into a wheel size; the table and fit check below confirm it in the shop.
Height → wheel size
| Wheels | Height | Age (guide) |
|---|---|---|
| Balance bike (10–12″) | 82–110 cm | 2–4 |
| 12″ | 85–105 cm | 2–4 |
| 14″ | 95–112 cm | 3–5 |
| 16″ | 105–122 cm | 4–6 |
| 20″ | 115–138 cm | 6–9 |
| 24″ | 130–148 cm | 8–11 |
| 26″ and adult frames | 142+ cm | 10+ |
FAQ
What height is a 16-inch bike for?
16″ wheels fit roughly 105–122 cm — usually ages 4–6. At 118–120 cm consider 20″ instead: a 16″ would last a single season.
Balance bike or training wheels?
A balance bike teaches the hard part — balance — so kids usually skip training wheels entirely afterwards. The typical path today: balance bike from 2, then a 14–16″ pedal bike without training wheels from 4–5.
Can you buy a bike to grow into?
Half a size at most, within the height range in the table. An oversized bike is heavier, taller and harder to control — scary to ride, so it stays in the garage. Track height with our height predictor and growth percentiles.