How to Measure Your Bra Cup Size? Step 1: Measure your bust from the fullest part using a measuring tape and note down the number. Since this reel is for demonstration purposes, our model is wearing clothes but we recommend measuring yourself without wearing anything for the most accurate result. Make sure to stand straight and avoid slouching while measuring around the fullest part of your bust. Step 2: Now, measure your underbust (waistline area) and note that number as well. If your measureme