Bust
Measure around the fullest part, while wearing your usual undergarment.
Waist
Measure the lower part of your bust.
Shoulder Width
Hold the tape at the shoulder point. Measure total width from shoulder bone to shoulder bone across the top spinal bone. The total length in inches is your full shoulder width..
Circumference of Arm Pit
Hold the tape at the shoulder point. Run the tape under the arm, pulling comfortably, and up to the shoulder point again in front. The total measurement is your armhole circumference.