This calculator estimates bra size based on bust size and band size (frame size). To ensure accuracy, measure to the nearest ¼ inch or ½ cm. This calculator provides results for the United States, the United Kingdom, European Union, France, Belgium, Spain, Australia, and New Zealand.
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 the 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 Size FR/BE/ES EU (Standard EN 13402) US and UK AU, NZ
XXS 75 60 28 6
XS 80 65 30 8
S 85 70 32 10
M 90 75 34 12
L 95 80 36 14
XL 100 85 38 16
XXL 105 90 40 18
3XL 110 95 42 20
4XL 115 100 44 22
5XL 120 105 46 24
Cup Size
The cup size can be calculated using the difference between bust size and band size. Refer to the table below.
Bust/band difference in inches US cup size UK/AU cup size
<1 AA AA
1 A A
2 B B
3 C C
4 D D
5 E or DD DD
6 F or DDD E
7 G or DDDD F
8 H FF
9 I G
10 J GG
11 K H
12 L HH
13 M J
14 N JJ
In Continental Europe, the cup size is calculated from the bust-to-band difference in centimeters.
Bust/band difference in cm Continental Europe cup size
10-11 AA
12-13 A
14-15 B
16-17 C
18-19 D
20-21 E
22-23 F
24-25 G
26-27 H
28-29 I
30-31 J
32-33 K
Frequently Asked Questions
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Why do bra sizes differ between countries?
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