Bra Size Converter
Example: US 34C = EU 75C = UK 34C
Shopping for bras internationally? This converter helps you find your size across different regions. Enter your band and cup size to see equivalents in US, EU, and UK sizing, along with sister sizes that might also fit.
All Sizes
US Size
EU Size
UK Size
US Band
EU Band
UK Band
Sister Size (Band Up)
Larger band, smaller cup - same volume
Sister Size (Band Down)
Smaller band, larger cup - same volume
How We Calculate This
Band conversions: EU = (US - 30) × 2.5 + 60. Cup sizes follow standard international equivalency charts. Sister sizes maintain the same cup volume across adjacent band sizes.
Methodology last reviewed: February 2025. How SparkCalc works
Sources: ISO 8559-1:2017: Size designation of clothes: Anthropometric definitions for body measurement · ISO 3635:1981: Size designation of clothes: Definitions and body measurement procedure · ISO 8559-2:2017: Size designation of clothes: Primary and secondary dimension indicators
Frequently Asked Questions
What are sister sizes?
Sister sizes have the same cup volume but different band sizes. If your regular size doesn't fit perfectly, try a sister size: one band size up with one cup size down, or vice versa.
Why are EU bra sizes different?
EU uses centimeters for band size instead of inches. A US 34 equals EU 75. Cup sizing is similar but uses continuous letters (E, F, G) instead of DD, DDD.
How do I measure my bra size?
Measure your underbust for band size and the fullest part of your bust for cup size. The difference between these two measurements determines your cup size.
Why do UK and US cup sizes differ?
After D cup, the systems diverge. US uses DD, DDD, then G. UK uses DD, E, F, FF, G, GG. The same physical cup might have different labels.
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