We recommend ordering the next size up for a child that is in-between sizes. The chest is the most important measurement for tops and dresses. The waist is the most important measurement for bottoms.
Measuring tips: Wrap a measuring tape around the fullest part of the child's chest, under the armpits and across the shoulder blades. The child should be standing and relaxed.
To measure the waist, wrap the measuring tape around the smallest part of the waist. The tape should be snug, not tight. If you do not have a measuring tape, use a string and measure against a ruler or yardstick.