Please note all conversions are approximate and may vary by label, brand, or personal preference of fit. Measure Method Bust Measure under your arms at the fullest part of your bust. Keep the tape level. Waist Measure around your natural waistline, keeping the tape comfortably loose. This is the narrowest part of the body between the ribs and the hips. Hips Stand with your feet together and measure around the fullest part of your hips. Notice: If you don't prefer tight fitting or too much support, you may size up.