Bra Size Converter

Bra sizing uses band size (around the ribcage) and cup letter (volume relative to band). US and UK often share band numbers; EU bands use centimeters (70, 75, 80…). Cup letters are not identical across regions — DD in US may map to E in EU.

This converter uses common retail crosswalks for standard sizes. Full-bust and specialty brands use different grading — always try on or check the brand chart before buying.

Example: US 34C ≈ UK 34C, EU 75C. US 36DD ≈ UK 36DD, EU 80E. Underbust in cm is approximate from the EU band label.

Band size is the ribcage measurement under the bust; cup letter is volume relative to that band. EU bands are labelled in centimetres (70, 75, 80…), while US and UK bands commonly use even inch numbers (32, 34, 36…). A US/UK 34 roughly aligns with EU 75.

Cup letters diverge more as sizes grow. US and UK often match through C and D, but US DD commonly maps toward EU E, and larger cups diverge further by brand. Treat converted cups as try-on guidance, not exact equivalence.

Sister sizes keep cup volume while changing band: 34C and 32D are sister sizes. This converter does not compute sister sizes — if a band feels tight but cup volume is right, try the sister size on the brand chart rather than only converting regions.

Fit depends on band tension and cup depth, not the label alone. Remeasure when switching brands, and again during pregnancy or nursing when band and cup can change independently.

Sports bras and many bralettes ignore traditional cup letters or use S–XL. This converter targets underwire-style band-and-cup labels; use the brand's athletic chart for compression styles.

Bra fit depends on band tension and cup depth, not label alone — try on when switching brands even after converting sizes.

Sports bras and bralette sizing may ignore cup letter — this converter targets underwire bra labels.

UK and US cup letters diverge at larger cup sizes — treat converted cups as try-on guidance, not exact equivalence.

Nursing and pregnancy change band and cup independently — remeasure rather than converting old labels alone.