When should my child transition from junior to adult ski boots?

Most children transition when they reach approximately mondo size 22.0-23.0, which is where junior sizing ends and adult sizing begins. However, the transition should also consider the child's weight and skiing ability. A small, light 13-year-old in a mondo 23.0 junior boot may be better served staying in junior boots for the softer flex, while a heavy, aggressive 11-year-old in the same size might benefit from the performance of an adult boot. When transitioning, start with a soft-flex adult boot (70-80 flex) rather than jumping to a stiff model.