Bra Size Calculator & Converter

Find your bra size from measurements, or convert between US, UK, EU, FR, and AU sizing systems.

Measurement unit

Underbust (in)— snug under bust

Bust (in)— fullest part

Your Bra Size (US)

30DD

Sister sizes (same cup volume, different fit)

28DDD/F

30DD

32D

34C

System	Band	Cup	Full Size
US / Canada	30	DD	30DD
UK	30	DD	30DD
EU (cm)	75	E	75E
FR / BE / ES / IT	90	E	90E
AU / NZ	30	DD	30DD

How to measure: Stand upright and breathe normally. Measure underbust snugly just below the breasts. Measure bust at the fullest point, keeping tape level. Try the calculated size and adjust — fit varies by brand and style.