Arm length – Measure arm length from neck to wrist fold along the top of the arm with the arm fully extended.
Chest – Measure horizontally around the fullest part of the chest.
Waist - Measure horizontally around the narrowest part of the waist, your natural waist, at the small of the back or where your body bends if you lean to the side.
Leg Length - Measure from the crotch (top of inner thigh) to where you would want the hem to sit on your foot or shoe.