There are two elements to consider when choosing the size of a child's bike: age and height. Here you can find information that combines these two factors and can guide your choice. Inches are given, which refer to the size of the wheels (all components of the bike are adjusted accordingly). Children 1-3 years old, height up to 90 cm: 12″ - for this age range we recommend the BALANCE BIKE to start learning the balance of two wheels Children aged 3-4 years, height from 90 to 105 cm: 14″ Children aged 4-5 years, height from 105 to 120 cm: 16″ Children of 6-7 years, height from 120 to 135 cm: 20″ Children of 8-11 years height from 135 to 155 cm: 24″ Children over 155 cm: we recommend size 27.5″