Kids bikes are sized by wheel diameter, matched to the child height and inseam — not by age alone, since kids of the same age vary a lot.
| The child height | Recommended size |
|---|---|
| 85 to 100 cm tall (about age 2 to 3) | 12 in wheels (or balance bike) |
| 95 to 110 cm tall (about age 3 to 4) | 14 in wheels |
| 105 to 120 cm tall (about age 4 to 6) | 16 in wheels |
| 115 to 135 cm tall (about age 5 to 8) | 20 in wheels |
| 130 to 150 cm tall (about age 7 to 11) | 24 in wheels |
| 145 to 162 cm tall (about age 10 to 13) | 26 in wheels or small adult frame |
| under 85 cm tall (toddler) | Balance bike (no pedals) |
| Still learning to balance | Pick the smaller wheel size so feet reach the ground. |
| Confident rider | Size up to the larger wheel for more room to grow. |