This Fit Chart is here to assist you in manually determining your bra and cup size. Step 1. - Take the tape measure and place it around your body directly below the bust. - Ensure that the tape is firm and is not over the bra or underwire. - This measurement is your size. The chart below will assist you to find Step 2. - The next step is to measure across the fullest part of the bust. - Place the tape measure around your back firmly and then over the middle of the bust. - Your cup size will be calculated by the difference between this measurement and the bra size measurement. This chart is only a guide. If your measurements seem inconsistent or inaccurate please consult a fitting specialist at your closest department store to measure you correctly.