How to measure -- Boys' Sizing
Measure around widest part of head, at forehead.
With elbow bent, measure from the center (back) of neck to elbow and down to wrist.
Measure around the widest part of chest, about an inch below the armpits.
Measure over mid-shoulder, down the back, through the crotch and up over right chest, back to the starting point. With diaper on if applicable.
Measure above the belly button, just below the ribs.
Measure the maximum horizontal circumference around the hips, taken where the rump sticks out back the most.
Measure from midpoint of the crotch to bottom of foot, along inner side of leg (no shoes).
Measurements refer to body size, not garment dimensions, and are in inches unless otherwise noted.