Size Converter
International Bra Size Converter
Convert a bra size between international systems without treating every label as perfectly interchangeable. We show the closest equivalent, cup-sequence differences and any conversion that may require extra care.
Convert a size you already know
Enter a size you currently wear and see the closest equivalent in other systems.
Why bra size conversion is not always one-to-one
A band number and a cup letter each convert through their own rules, and those rules diverge between systems in ways that a single lookup table can hide:
- UK and US cup-letter sequences agree up to a D cup, then split - the US market has no single agreed label for the position after D, so some brands use DD, others DDD, others E or F for what is the same cup volume.
- French band numbers and EU band numbers describe the same underbust in centimetres, but the French number is offset from the EU number rather than identical to it.
- Australian and New Zealand bands are usually written as even numbers close to the UK band number, but the cup sequence underneath follows the UK pattern, not the US one.
- An individual brand's own size chart can differ from the general system conversion, especially once a style uses moulded cups, a firmer band, or a different fabric blend.
- Construction and material change how a labelled size behaves, which a system-to-system conversion cannot see or account for.
Bra size systems explained
- UK
- Band in inches, cup letters that double past H (HH, JJ) rather than jumping to a new letter.
- US / Canada
- Same band numbers as the UK, but the cup sequence is brand-dependent past a D cup.
- EU
- Band in five-centimetre steps, a single-letter cup sequence with no doubled letters.
- France / Belgium / Spain
- Uses the EU cup logic with its own band-number offset.
- Australia / New Zealand
- Band numbers close to the UK system, cup sequence following the UK pattern.
- Japan
- Band in five-centimetre steps like the EU system, with its own labelling conventions and notable brand variation.
Before ordering from another country
- Confirm whether the product uses the brand's home-country system.
- Check the exact cup sequence the brand publishes, rather than assuming a general conversion.
- Read whether the band is described as firm or flexible.
- Order the starting size and a nearby alternative when returns are practical.
- Judge the fit, not the printed conversion alone.
Frequently confused conversions
- UK E vs US DDD/F - the same cup volume, different brand-dependent US labels.
- EU 75 vs FR 90 - the same underbust, two different band numbering conventions.
- UK 34 vs AU 12 - both describe a similar band, using unrelated numbering systems.
- UK double letters (DD, FF) vs the US progression, which doesn't double letters the same way.