Bra Size Calculator

bust size smaller than frame size?
Bust Size
Frame Size
  bra size

The bust size is the loose circumference measured around the chest over the fullest part of the breasts, while standing straight with arms to the side, and wearing a properly fitted bra.

The frame size is the firm circumference measured directly underneath the breasts.



Incorrect bra fit

Surveys and studies often cite that anywhere between 70-85% of women wear incorrectly fitted bras. While data collection methods between various sources is not consistent and these percentages may be inflated, incorrectly fitted bras are nonetheless a significant issue, evidenced by the number of studies, articles, and complaints surrounding the issues women face due to a lack of size standardization. Studies have revealed that the most common mistake made by women when selecting a bra was to choose too large a back band and too small a cup. Part of the issue is lack of standardization regarding band and cup sizes. These vary largely between countries, and even manufacturers, making it difficult to use these measures as anything more than an approximate fit. A 34B bra from two different companies for example, may not fit the same person because of this lack of standardization.

Some signs of incorrectly fitted bras include the band digging into the torso or sliding upwards, red marks, shoulder or neck pain, the breasts overflowing around the edges of the bra, and the bra's center panel not lying flat against the breast, among others.


Bra size

The two major aspects of bra size are the band size and the cup size.

Band size (frame size)

The band size is the size of the bra band around the torso. However, band sizes come in different measurements in different countries, in that sizes such as small, medium, and large, equate to different measurements. Refer to the table below for some size measurements, though some variation from the published measurements is possible.

Band SizeFrame size measurement in cmEU (standard EN 13402)USA and UK
XXS58-626028
XS63-676530
S68-727032
M73-777534
L78-828036
XL83-878538
XXL88-929040
3XL93-979542
4XL98-10210044
5XL103-10710546

Cup size

The cup size can be calculated using the difference between bust size and frame size. Refer to the table below.

Bust/frame difference in inchesUS cup sizeUK/AU cup size
<1AAAA
1AA
2BB
3CC
4DD
5E or DDDD
6F or DDDE
7G or DDDDF
8HFF
9IG
10JGG
11KH
12LHH
13MJ
14NJJ


Bust/frame difference in cmContinental Europe cup size
10-11AA
12-13A
14-15B
16-17C
18-19D
20-21E
22-23F
24-25G
26-27H
28-29I
30-31J
32-33K