Just use a tape measure, bust: wrap a tape measure around your back and nipples along your shoulder blades. Don't make the tape measure too tight. Bracket circumference: 1, relax your arms and wrap the tape measure around the biceps brachii. 2. Bend the forearm hard and wrap the tape around the top of the biceps brachii. Waist circumference: the tape measure wraps around three fingers above the ilium. Make a record after each measurement, so that you can know whether your chest circumference has changed.