Bra Cup Sizes Explained: The Complete Measurement Guide

What Is a Cup Size?

Cup size refers to the alphabetical measurement (A, B, C, D, etc.) representing the difference between your bust measurement and band measurement. It indicates breast volume relative to torso size in bra sizing systems.

How to Calculate Cup Size in 3 Steps

  1. Measure Band Size:

    Wrap measuring tape snugly under bust (inches/cm)

  2. Measure Bust Size:

    Measure around fullest part of breasts

  3. Determine Cup Size:

    Subtract band from bust measurement. Use chart:

    Difference Cup Size
    0-1" (0-2.5cm) AA
    1-2" (2.5-5cm) A
    2-3" (5-7.5cm) B
    3-4" (7.5-10cm) C
    4-5" (10-12.5cm) D

5 Essential Cup Size Facts

  • ✧ Cup sizes vary internationally (US vs UK vs EU)
  • ✧ Weight changes affect cup size accuracy
  • ✧ Breast shape impacts cup fit (shallow vs projected)
  • ✧ 80% wear wrong cup size (Leeds University study)
  • ✧ Proper fit has 0.5-1" space between cups

International Cup Size Comparison

US UK EU Bust-Band Diff
C C C 3-4"
D D D 4-5"
DD DD E 5-6"
DDD E F 6-7"

Professional Fitting Checklist

  • ✓ No breast tissue spillage
  • ✓ Center panel lies flat
  • ✓ Underwire follows breast root
  • ✓ Straps don't dig in

When to Remeasure

  • ● After 5-10lb weight change
  • ● Post-pregnancy/breastfeeding
  • ● Every 6-12 months
  • ● Changing birth control
Back to blog

❤️ Reliable Shipping Support: Receive your order within 3 to 14 days with Irene's Secret's swift processing and delivery, ensuring prompt and perfect arrival.

❤️ Irene's Secret: A professional and trustworthy lingerie store offering high-quality products and exceptional customer service. The team is dedicated to exceeding your expectations.

❤️ Connect with Us: Follow Irene's Secret on Pinterest, Facebook, and Twitter for updates, special offers, and fashion inspiration, and join a vibrant community of fashion enthusiasts.

Blog posts

View all
1 3
View all