What Do The Letters On Bra Sizes Mean

Complete Explanation

Bra sizes consist of a number (the band size) and a letter (the cup size). The number represents the circumference of the ribcage just under the bust, measured in inches (e.g., 34, 36). The letter indicates the cup volume, which is the difference between the fullest part of the bust and the band measurement. Each increase in the letter (e.g., from A to B, B to C) typically corresponds to an additional inch of difference, though this varies by sizing system and brand.

• A Cup:
  The smallest standard cup size. Represents approximately a 1-inch difference between bust and underbust measurement.
• B Cup:
  Represents about a 2-inch difference. Larger than A for the same band size.
• C Cup:
  Represents about a 3-inch difference. Common medium cup size.
• D Cup:
  Represents about a 4-inch difference. Larger than C.
• DD (E) Cup:
  Represents about a 5-inch difference. In US sizing, DD is equivalent to E in UK sizing. Beyond D, letters often double (e.g., DDD/F, G, H).
• Beyond DD:
  Sizes continue alphabetically (e.g., E, F, G, H) or with double letters (e.g., DDD, G, H). The specific progression varies by country and manufacturer.

History / Background

The modern bra sizing system originated in the early 20th century. In 1935, the Warner company introduced the first systematic cup sizing using letters A, B, C, and D. Previously, bras were sold by bust circumference only. The letter system was based on the difference between the bust and underbust measurements, with A being the smallest. Over time, additional letters (DD, DDD, etc.) were added to accommodate larger busts, and international variations developed, such as UK (AA, A, B, C, D, DD, E, F, FF, G, GG, H, HH, J, JJ, K) and EU (using cm and different letter progressions). The system became widely adopted in the mid-20th century, though inconsistencies between brands still exist.

Importance and Impact

Bra size letters directly affect fit, comfort, and support. An incorrect cup size can lead to shoulder pain, breast tissue discomfort, and inadequate support during physical activity. The letter system has influenced lingerie design, retail sizing standards, and medical advice regarding breast health. Studies indicate that a majority of women wear incorrectly sized bras, partly due to misunderstanding the meaning of letters. The system also impacts fashion, as different cuts and styles (e.g., plunge, push-up) interact with cup size. Additionally, the letter system has cultural significance, often being used as a shorthand for breast size in media and casual conversation.

Why It Matters

Understanding bra size letters helps consumers make informed purchasing decisions, both in stores and online. A correct fit reduces discomfort, improves posture, and can prevent skin irritation or back pain. For individuals with larger cup sizes, knowing the letter progression (e.g., DD vs. E) is essential to finding bras that offer adequate coverage and support. The knowledge also aids in navigating sizing differences between brands and countries, such as US versus UK cup scales. Proper bra sizing contributes to overall well-being and confidence.

Common Misconceptions