Is a 42 C bra size same as a 40 D?

A 42C and a 40D bra size are not the same, though they are relatively close. The number (42 vs. 40) indicates the band size, while the letter (C vs. D) represents the cup size. A 42C has a larger band size but a smaller cup size compared to a 40D, which has a smaller band but a larger cup. Generally, the cup volume of a 42C is slightly less than that of a 40D.