Measuring your child properly will help ensure a good fit.  Starting with your child in the diaper you plan to use under your knit pants, measure the waist.  The waist is where you would like the top of the pants to lay.  Next measure the hips around the largest part of the diaper near the hips and thighs.  The rise is measured from the top of pants, between the legs, to the to the back where you would like your pants to lay.  Measure your inseam from the child’s crotch to the ankle.