International bra size conversion guide

Why conversion tables disagree

Every published conversion table is true somewhere and approximate everywhere. The disagreements have three sources. First, band bases: US and UK charts count even inches around the underbust, European charts round the underbust in centimetres to a 5 cm step, French bands are offset from the European number, and Australian charts run their own even scale. Second, cup letters above a D: the US sequence doubles letters while the UK and European sequences introduce new single letters, so letter-for-letter matching fails exactly where it matters most. Third, publisher choices: rounding direction, the measuring point for the cup difference, and where each chart chooses to double letters all vary, which is why two reputable tables can differ by a step at the same size.

The practical consequence for a buying desk is that conversions are label arithmetic, not fit translation. They move a garment between naming systems; they do not promise that a wearer fitted in one market finds the same feel in another, because fit expectations and grading bases also differ by market. That limit shapes the protocol at the end of this note.

Units add a further wrinkle. Consumers in inch-based markets measure in inches, consumers in metric markets in centimetres, and the rounding conventions differ so thoroughly that a wearer converting her own measurements across systems can land a band and a letter away from her converted label. Retailers respond with dual labeling - both conventions printed on the same hangtag - which is now common in international assortments and costs little at the label supplier. The desk treats dual labeling as the default for export programs unless a market's rules or the brand's positioning say otherwise.

Band conversion across regions

Bands convert cleanly because the underlying measurement - the underbust - is the same body circumference everywhere. The commonly published mapping, hedged by the rounding conventions above:

Three regularities make the table memorable. The European number is the underbust in centimetres rounded to a 5 cm step. The French number is the European number plus 15, a bookkeeping offset rather than a different measurement. The Australian number tracks the US number minus 22. Italy publishes its own scale on a different basis again, which is why the table omits it; Italian labels are converted against the plant's own grid rather than from a general rule.

Cup letters above D

Below a D the letters agree well enough that most charts treat them as identical. Above a D they diverge, and the workable method is positional: count steps away from D instead of comparing letters.

The UK sequence continues with doubled-letter pairs - FF, G, GG, H, HH - which is why letter-for-letter conversion collapses above a D: there are more letters than positions in some systems and fewer in others. Counting steps survives every sequence, and it is how the desk writes conversions internally: as step counts plus one authoritative letter sequence, not as a wall of equivalences.

Conversion is not fit translation

A correct conversion puts the wearer in the right cell of the target chart. It does not promise the same experience in that cell, for three reasons. Grading bases differ: a European 75C is graded from a European block whose cup depth, wire curvature and band rise reflect that market's historical fit assumptions. Style assortments differ, so the constructions available in one cell vary by market. And consumers are calibrated to their domestic charts, which means a correctly converted label can still read as wrong to the wearer who has never seen it. None of this argues against conversion; it argues for separating the label question from the fit question, which the sizing and fit guide keeps explicitly apart.

Return rates make the distinction expensive to ignore. A range exported without local fit validation generates a predictable complaint pattern: the converted label is arithmetically right and the wearer still returns the garment because the band, the cup distribution or the strap set does not match what the domestic assortment taught her to expect. Brands that fit-test the destination market with a small sample run before the main order absorb the finding at sampling cost; brands that skip it absorb it as returns. The desk's recommendation is always the former, and the sampling timelines that make it affordable are on the lead time page cited below.

A conversion protocol for export programs

Serving several markets from one production range is a documentation exercise, and the desk runs it in four moves. Fix the master grid first: band run, cup run and diagonal families, written as body measurements with tolerances. Derive per-market labels from the master grid using the tables above - never the reverse, because grading from an inherited foreign chart imports someone else's boundaries. Fit-test the master grid, not each local label: the garment is one garment, and the labels are names for its cells. Then bind the paperwork: fiber content, origin and care labeling follow each destination market's rules, covered in the labeling note and the wider set on the compliance page.

Costs follow the label count only lightly - hangtags and printed labels are minor items - but the SKU structure follows the master grid directly, and minimums are quoted per color across the size ratio. Reference minimums and lead times are on MOQ and lead time; a brief listing the destination markets and the intended grid fits the quote form as-is, and the desk returns the per-market label sheet with the program documents.