Bra Size Calculator

How to Determine Your Bra Size

Understand what determines bra size, including band, bust, and cup logic across different countries.

What Determines Bra Size?

  • Bra size is determined by two main measurements: band size and cup size.
  • Band size refers to the measurement around your ribcage, just below your bust.
  • Cup size is determined by the difference between your bust measurement and band measurement.
  • The combination of band size and cup size gives you your complete bra size (e.g., 34B).

Band Size Logic

  • Band size is measured in inches or centimeters around your ribcage.
  • It should be snug but not tight - you should be able to breathe comfortably.
  • Band sizes typically range from 28 to 46 inches (or 60 to 105 cm in EU sizing).
  • The band provides the main support for your bra, so it's crucial to get this measurement right.

Cup Size Logic

  • Cup size is calculated by subtracting your band size from your bust size.
  • Each inch (or 2.54 cm) of difference corresponds to a cup size.
  • Cup sizes progress alphabetically: AA, A, B, C, D, DD, DDD, etc.
  • The same cup size can look different on different band sizes due to the scaling.

International Sizing Differences

  • US and UK sizing use the same band size system but may differ in cup size progression.
  • EU sizing uses centimeters for band measurements and different cup size letters.
  • French/Belgian/Spanish sizing uses a different numbering system for band sizes.
  • Australian/New Zealand sizing uses a unique numbering system similar to UK sizing.

Important Notes

  • Bra sizing is not an exact science - it's more of an art that requires some trial and error.
  • Different brands may fit differently even with the same size label.
  • Your bra size can change over time due to weight fluctuations, pregnancy, or aging.
  • It's recommended to get professionally fitted every 6-12 months.
  • The +4 rule (adding 4 inches to band size) is outdated and not recommended for modern bras.

Ready to Calculate Your Size?

Now that you understand how bra sizing works, use our calculator to find your perfect fit.

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