We recommend that although the measurement picture here shows to measure on the "absolute" waist, it is likely your child will wear their waistband much lower than this to avoid the 'Simon Cowell' effect. So, find the place where your child's waistband would comfortably lay, and measure around their middle at that point. Order the nearest waist size at this measurement. For example, if the measurement you make at the most comfortable place around your child's tummy is 29 inches, you would choose our size 4.