The above measurements are based on measuring one side of the garment to the other when the garment is laid flat. 

How to Measure:

For accurate measurements, wear a tight vest or your underwear.
BUST: Measure around the fullest part of your bust, with your arms relaxed by your side.
WAIST: Measure around the narrowest part of the waist.
HIPS: Measure around the fullest part of your bottom.
SLEEVE: Measure from the tip of your shoulder bone to the cuff, with a slight bend in the arm.