With good posture, wrap a measuring tape under your arms around your back and take the measurement at fullest part of your chest. Be sure to keep the measuring tape parallel to the floor.
2. Measure your waist
Our waist can be a difficult area to measure! The natural waistline is halfway between the lowest rib you can feel and the top, outside edge of the hip bone. One trick might help you find this spot are to stand up straight and tilt over. Where your torso creases is where your waistline is.