I am very confused about how to order a bra sized bikini top. My daughter measures 28 inches for the band and her bust measurement is 36 inches. So for a regular bra, that is size 32D. (See Wonderbra for directions to calculate this). I wasn't sure, so I ordered several sizes of this bikini top. The one that fit her is the 30G. So the number is pretty close to her band measurement and the letter (counting one inch per letter) is pretty close to the difference between her bust measurement and band measurement. If it were exactly the same, she would wear a 28 H in the bathing suit. The funny thing is, I measure 32 inches in the band and 36 in the bust and wear a 36A bra. I tried on the 32C and it fit me, so I kept it! (You may have guessed: she is adopted. We definitely don't share a gene pool!). So the moral of this story is to use your band measurement for the number. Subtract that number from your bust measurement to get the letter, with 1=A, 2=B, 3=C, etc. , perhaps making the letter one notch lower than you count.Otherwise, we like the swim suit very much. I did make one alteration, though. My daughter did not like the halter style so I sewed the straps to the back of the band. I kept mine as a halter style. Also, she is young and opted for the skimpier bikini bottom and I kept the one that covers more and has a fold down "collar" at the hips. The bikini bottoms were true to size. Good luck!XI am a 34D and I ordered the 34D. Lo and behold - it fits just like a 34D should! Supportive, no bulges, no gaps, no slipping straps. And the material is cute and vibrant.Love this bikini top! The fit is spot on! Well made with a pretty design!The cups are a bit odd shaped but I love the print and style!True to size. Love this! Got a 38E and it fit perfect!The material and pattern of this bikini style is stunning and of high quality, however, the tailoring is funny. Moreover, there is a significant difference between the sizes. I had to try 4 different bras to get something that fits me. This last one, although size 30D fit me perfectly, while I am actually by all standards and all brands a regular size 30B. My advice is that you need to buy a few and try on to see what fits. On the other bra models of this range 30C was so small that it was barely an A cup. I so much loved the material and the vibrant colors that I kept on ordering another and another until I got the right fit.The bikini is neon, not as shown.I can do cartwheels on the beach and everything stays put!Perfect fit well impressedHoliday great look comfortable feels nice