Actually, a 34C is a slightly smaller boob size that a 38B, if my research is right. A 38B = 36C = 34D. As the band size goes down one the cup size goes up one. I felt all cool about my boobs getting bigger because I went from a 38B to a 34D and the woman at the store showed me a chart with the measurement of the breast itself and all three of them were exactly the same (from just under the arm where the breast starts, around the front, down to the ribs where the breast stops). Here is the chart, though I can't make it format to line up side by side.
Determining Bra Size & Cup Size
Studies show that the vast majority of women wear the wrong bra size. You may think that bra shopping will be easier after breast augmentation, but this is not always the case. Bra sizes run differently according to style and manufacturer. For example, if you buy a 34D bra from Victoria's Secret, this does not mean that you will always wear a 34D in all of their bras. Ditto for other manufacturers.
Implants tend to be wider than a "natural" breast, therefore, many of us will need to wear a D cup, simply because the width of a C cup bra isn't enough.
We have our own chart here at Just Breast Implants, which works for most, but not all, people. If it does not work for you, you may want to go to and be measured by a professional, though this does not always work either.
To use the chart below, y ou will want to measure each breast. Use a soft tape measure to do this. Start where the breast starts at (near the side/armpit), and measure all the way across the fullest part of the breast. The fullest part of the breast is usually the nipple, but not always.
You will also want to measure the circumference of your ribcage. Do this by measuring just below the breast, in the area of the crease. Measure all the way around. This is your ribcage measurement.
If your ribcage measurement is an odd #, add 5" to get your band width. Example: 29" ribcage + 5" = 34" band.
If your ribcage measurement is an even #, add 4" to get your band width. Example: 28" ribcage + 4" = 32" band.
Click here for photos of how to measure (
this link obviously doesn't work, it does work on the original website
32" band (27-28" ribcage):
6"=A
6.5"=Full A
7"=B
7.5"=Full B
8"=C
8.5"=Full C
9"=D
9.5"=Full D
10"=DD
10.5"=Full DD
11"=E
11.5"=Full E
34" band (29-30" ribcage):
7"=A
7.5"=Full A
8"=B
8.5"=Full B
9"=C
9.5"=Full C
10"=D
10.5"=Full D
11"=DD
11.5"=Full DD
12"=E
12.5"=Full E
36" band (31-32" ribcage):
8"=A
8.5"=Full A
9"=B
9.5"=Full B
10"=C
10.5"=Full C
11"=D
11.5"=Full D
12"=DD
12.5"=Full DD
13"=E
13.5"=Full E
38" band (33-34" ribcage):
9"=A
9.5"=Full A
10"=B
10.5"=Full B
11"=C
11.5"=Full C
12"=D
12.5"=Full D
13"=DD
13.5"=Full DD
http://www.justbreastimplants.com/size/