Children should have a good fitting ski boot too. Many parents size ski boots by the size of shoes the child wears. While wearing a pair of sneakers too big, doesn't hinder walking, wearing too big of ski boot can be unsafe. Ski boots are sized in cm, or mondo size. It's always best to have a trained boot fitter check the size and flex of the boots before you make your decision. Anticipating growth is difficult and going too large in a ski boot makes skiing more difficult and unsafe. And a boot too soft, they'll have a lack of control. A boot too stiff, and it will make turning more difficult. Ski boots should always be worn and tried on with the proper ski socks for the best fit. A happy kid makes for a happy mom and dad.