Sizeguide bras Here are tips on how to find the right size when you buy bras for pregnancy and nursing. Find your size Bra sizes normally consist of a number and a letter (for example 75C). The number shows the size of the underband and the letter represents the cup size. Once you have found your size (number and letter) you can consult the chart below to see which size to order when buying a Boob Seamless BH. First you need to take your measurements. So find a tape measure, put on a soft unpadded, non-wired bra, and breathe out! Taking your measurements Measure across the fullest point of your bust (A) and measure under the bust (B). Size of underband The under-bust measurement (B) shows the size of your underband. Under bust EU FR/ES/BE UK/US 68-72 cm 70 85 32 73-77 cm 75 90 34 78-82 cm 80 95 36 83-87 cm 85 100 38 88-92 cm 90 105 40 93-97 cm 95 110 42 98-102 cm 100 115 44 Cup size The difference between the measurement across the fullest part of your bust (A) and the under-bust measurement (B) gives your cup size: A - cup: 12-14 cm difference B - cup: 14-16 cm difference C - cup: 16-18 cm difference D - cup: 18-20 cm difference E - cup: 20-22 cm difference F - cup: 22-24 cm difference EU UK US A A A B B B C C C D DD D E E DD/E F F DDD/F G G DDDD/G Size guide 70 75 80 85 90 95 100 A S S S M L L B S S M M L L XL C S M M M L L XL D M M M L L XL XL E M M L L XL XL XL F L L L XL XL XL G L L XL XL XL XL Read our tips and advice when choosing a nursing bra! Guide to all our Fast Food nursing bras.