To get the measurement of the circumference of your chest, start by placing one end of the tape at the fullest part of your bust and circle under your armpits, around your shoulder blades, and back to the front.
Circle your waist with the tape at your natural waistline which is located above your belly button and below your rib cage. Do not suck in your stomach, it will distort the measurement. If you bend to the side, the crease that forms is your natural waist line.
Measure around the largest part of your buttocks. You can use a mirror to make sure the measuring tape is level at the back. Start at one hip and wrap the tape around your rear, around the other hip, and back to where you started.
You can measure the inseam in two ways: Have a friend stretch a measuring tape from your crotch to the bottom of your ankle. Or, if you have a pair of pants that fit you perfectly, you can measure the inseam yourself: Just stretch the tape from crotch to hemline.
Measure the circumference of the fullest part of your thigh. Wrap the measuring tape around your thigh from front to back and then around to the front.
Upper Arm Measurement
Wrap the measuring tape around the widest part of your upper arm from front to back and around to the start point.
General Tips for Measuring
To get the most accurate measurements, use a cloth measuring tape instead of a metal one, and measure yourself on your bare skin, not over clothes - except the inseam. Also, make sure that when you measure your chest, waist or hips, the tape is level and not too tight or too loose.