In the image, the Upper Bust measurement is 34 inches. The block for a B Bust cup (blue lines)will fit a bust of 36 inches – 2 inches more than the Upper Bust. The block for a C Bust Cup (green lines)will fit a bust of 37 inches – 3 inches more than the Upper Bust.
Subtract your calculated band size (Step 1) from your bust measurement (Step 2) and refer to the bra cup size chart here. Your bra size is your band size with your cup size. Example: 37 inches (bust) – 34 inches (band) = 3 inches. That’s a 34C.
The bust-band difference for a C cup bra is around 3 inches. Again, C cups do not have double or triple letter sizes, so if you’re around 2.9 inches or 3.3 inches, you can go bigger or smaller in cup size. Did you know that the D cup is one of the most common sizes in the US, UK, and Europe?Bust cup size diagram