I make chaps and chinks from the smallest to the near adult sized youth.  As a parent, I know that you will want these chaps and chinks to fit for the longets possible time!  I always suggest, that you order your chaps and chinks as long as possible.  The waist and thigh openings are adjustble up to 8 inches, and that will give you plenty of growing space.  When order chinks, it is possible to measure then all the way to the ground, that way they will start out as chaps and end up as chinks.