Brassiere measurement

Brassiere measurements (also called brassiere sizes, colloquially bra sizes) are labeled differently depending on the system of standards set in various countries and vary from one manufacturer to another. They usually consist of a number, indicating a band size, and one or more alphabetical letters indicating the breast cup size. These sizing systems are typically used to label off-the-shelf bras and are not used for custom-made bras or bras built into other garments.

Finding the correct bra size can be difficult because manufacturers do not make bras according to a uniform standard. Some manufacturers have been found to deliberately mis-state the band size. Bra-fitting advice also varies considerably, and uniformly require the woman seeking to find a correctly fitting bra to already own one. Furthermore, the shape, size, symmetry, and spacing of women's breasts vary considerably, affecting the bra and cup size. Women's breasts change during their monthly period, during and after pregnancy, and due to weight gain and loss. Breasts that have been augmented and sagging breasts are shaped differently and require different kinds of bras. Even breathing can substantially alter the measurements. Obtaining the correct size is further complicated by the fact that the size and shape of a woman's breasts fluctuate during her menstrual cycle, and also with weight gain or loss. One study found that the label size was consistently different from the measured size.

Manufacturer standards vary
One issue that complicates finding a correctly fitting bra is that standardized band and cup sizes vary considerably from one manufacturer to another, resulting in sizes that only provide an approximate fit. Women cannot rely on labeled bra sizes to identify a bra that fits properly. In the United States, there is no formal standard defining the inch-based bra-size system. Unlike dress sizes, international manufacturers do not agree on a single standard. British bra brands can range in cup size from A to K, while most Americans can find bras with cup sizes ranging from A to G, although some brands go as high as L. However, as the cup size increases, the labeled cup size of different manufacturer's bras tend to vary in actual volume.

Scientific studies show that the current system of bra sizing is quite inadequate. Even medical studies have attested to the difficulty of getting a correct fit. Research by plastic surgeons has suggested that bra size is meaningless because breast volume is not calculated accurately:

Majority wear wrong sized bra
The results of a number of surveys and studies in many different countries show that between 70% to 100% of women wear incorrectly fitted bras. In a study of 103 women seeking mammoplasty, researchers concluded that "obesity, breast hypertrophy, fashion and bra-fitting practices combine to make those women who most need supportive bras the least likely to get accurately fitted bras." Their research found that bra measuring systems often lead women to choose an incorrect size, most commonly resulting in too large a cup size (by a mean of three sizes) and too small a band size (by a mean of 4 sizes).

Many studies have shown that around 80% of women are wearing the wrong size, with the most common mistake being to select a bra with too large a back band and too small a cup, for example, 38C instead of 34E, or 34B instead of 30D.

In November, 2005, Oprah Winfrey produced a show devoted to bras and bra sizes, during which she revealed research that eight out of ten women wear the wrong size bra.

Advertising influence
Manufacturers' marketing and advertising often appeals to fashion and image over fit, comfort and function. Since about 1994, manufacturers have re-focused their advertising, moving from advertising functional brassieres that emphasize support and foundation, to selling lingerie that emphasize fashion while sacrificing basic fit and function, like linings under scratchy lace.

Measurement difficulties
There are two primary methods for determining bra size and several variations on those methods. Calculating the correct bra band size is complicated by a variety of factors. Bra measurement is not an exact science. Normally a perfect fit can only be achieved by purchasing a custom-made bra, which takes into account the asymmetrical size and position of a woman's breasts on her chest. Bra experts recommend that women, especially those whose cup sizes are D or larger, get a professional bra fitting from the lingerie department of a clothing store or a specialty lingerie store. However, even professional bra fitters produce inconsistent measurements of the same woman. A 2004 study by Consumers Reports found that 80% of department store bra fittings resulted in a poor fit.

Some bra manufacturers and distributors state that trying on and learning to recognize a properly fitting bra is the best way to determine a correct bra size, much like shoes. However, most women do not know the math involved in calculating the size of a good-fitting bra. Obtaining the correct size is further complicated by the fact that the size and shape of a woman's breasts fluctuate during her menstrual cycle,, during and after pregnancy, and with weight gain or loss. One study found that the label size was consistently different from the measured size.

The British Chiropractic Association warned that wearing the wrong bra size can lead to a number of problems, including back pain, restricted breathing, abrasions, breast pain and poor posture. Many of the health problems associated with bras are due to fitting problems. Finding a correct fit can be very difficult for many women which has affected sales. Medical studies have also attested to the difficulty of getting a correct fit. Scientific studies show that the current system of bra sizing is quite inadequate.

Larger-breasted women tend to wear bras that are too small, and conversely, smaller-breasted women bras that are too large. Larger women are more likely to have an incorrect bra fit. This may be partly due to a lack of understanding of how to correctly determine bra size. It may also be due to unusual or unexpectedly rapid growth in size brought on by pregnancy, weight gain, or medical conditions including virginal breast hypertrophy. As breasts become larger, their shape and the distribution of the tissues within them changes, becoming ptotic and bulbous rather than conical. This makes measurements increasingly unreliable, especially for large breasted women. The heavier a woman's build, the more difficult it is to obtain accurate measurements, as measuring tape sinks into the flesh more easily. Finally, up to 25% of women's breasts display a persistent visible breast asymmetry, which is defined as differing in size by at least one cup size. Ten percent are severely different, with the left breast being larger in 62% of cases. Manufacturer's standard brassieres do not take these inconsistencies into consideration.

Band measurement methods
The band size is the size of the brassiere band around the woman's torso. Manufacturers assume women already own a well-fitting bra, as they recommend that women begin measuring while wearing an their best-fitting "unlined or lightly lined" bra. Variations of two methods are recommended, over the bust and under the bust. Only women whose breasts are firm and perfectly shaped can measure without a bra. A third method requires the woman to measure below, above and across her breasts.

Some bra fitters recommend that if a woman's torso measurement is between sizes, that she choose the next larger size. Others recommend rounding to the nearest whole number. The band size can be adjusted to a small degree using a series of hooks and eyes in the clasp.

Above the breasts
Both methods require a flexible dressmaker's tape measure. The first method, measuring horizontally around the torso above the bust, produces the actual band size, unless the number is odd. Because band sizes are only manufactured in even numbers, the wearer must round down or up to the closest even number. One method requires the woman to add 4 in if the measurement is even, or add 5 in if the measurement is odd.

Below the breasts
The second method requires the woman to measure in a horizontal line (parallel to the floor) around her torso, but under the bust. If the measurement is even, the wearer should add four or five to the number; If the number is odd, she should add five. Another variation advises the wearer to add five to the number of inches, unless the number is 34 or greater, in which case add only three.

International fitting standards
In countries that have adopted the European EN 13402 dress-size standard, the torso is measured in centimetres and rounded to the nearest multiple of 5 cm. Bra-fitting experts in the United Kingdom state that many women who buy off the rack without a professional assistance wear up to two sizes too small.

Band sizes vary around the world.

For example, the following sizes are all equal:

∗ US = United States of America; UK = United Kingdom; AU = Australia; NZ = New Zealand; EU = Europe; JP = Japan; B = Belgium; E = Spain; F = France; P = Portugal; I = Italy; CZ = Czech Republic.

Cup measurement methods


The cup size can be determined by calculating the difference between the bust size and the band size. The bust size, bust line measure, or over-bust measure is the measurement around the women's torso over the fullest part of the breasts, usually over the nipples, ideally while standing straight with arms to the side and wearing a properly fitted bra. These are measured in the same units as the band size, either inches or centimetres.

The cup size is based on the difference between the band size and the over-the-bust measurement.

Cup sizes vary from one country to another. The larger the cup size, the bigger the variation.

Measuring cup size without a bra
Women who have difficulty calculating a correct cup size may be able to find a correct fit using a method adtopted by plastic surgeons. Using a flexible tape measure, position the tape at the outside of the chest, under the arm, where the breast tissue begins. Measure across the fullest part of the breast, usually across the nipple, to where the breast tissue stops at the breast bone. This measuring approach assumes that the woman's breasts do not sag significantly so that measuring across the fullness of the breast is not practical. If the measurement is:

Cup volume
Most woman assume that a B cup on a 34 band is the same size as a B cup on a 36 band. In fact, bra cup size is relative to the band size, as the actual volume of a cup size changes as the band size changes. Because manufacturer's standards vary so widely, women cannot rely on a single measuring system. The volume of a brassiere cup is the same for 30D, 32C, 34B, and 36A. These related bra sizes of the same cup volume are called sister sizes. It is sometimes possible that two adjacent sister sizes will both fit a woman, since the cup volume is the same, while the band size can be adjusted to a small degree by using the hook and eye fasteners in the bra clasp.

Increasing size of common bras
In 2003 the most common bra size sold in the UK was 36C, while a more recent study showed that the most often sold bra size in the US in 2009 was 36DD, an increase of one cup size compared to 2008.

United States measurement systems
Bra labeling systems used around the world are at times misleading and confusing. In the United States, many bra manufacturers arbitrarily add four, five or even six inches to the band size, sometimes referred to as vanity sizing. The wearer mistakenly believes she is wearing a smaller sized bra band. The add 4 to 5" practice was devised by Warners in 1935, and the practice is still in use.

Older European systems
The EN 13402 standard was introduced in 2006, and a range of other cup-size definitions are still in use in Europe, using either centimeters or inches to indicate the under bust girth.

One common cup size system used by European manufacturers, in order of increasing size, is: AAA-AA-A-B-C-D-DD-E-F-FF-G-GG-H-J, although the use of double letters is not consistent between manufacturers (e.g. some may use EE rather than F, DDD rather than E, etc.). The majority of bra bands run true to size (as in, a size 36 band measures, when stretched, 36 inches). It is expected that the EN 13402 standard will eventually help resolve the current confusion surrounding cup-size codes in Europe.

Additional reading

 * Lingerie
 * Brassiere designs
 * History of brassieres
 * Wonderbra
 * Underwire bra
 * Cupless bra
 * Nursing bra
 * Softcup bra