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115J bra size

A 115J bra is cut for an underbust of 112.5–117.5 cm and a bust of 145–147 cm. Below it is the same size as every other system prints it, and the sister sizes that hold the same cup.

115J in every system

EU
115J
RU
115J
US
50J
UK
50GG
FR
130J
IT
10J
JP
115J

A starred letter continues that system’s published table rather than being taken from it — European charts stop at H, British ones run further, and the same breast is published in one and extrapolated in the other.

Where each notation comes from

What each notation means — why the British band reads 34 and the Italian reads 2 — is set out system by system on the bra size page.

Sources

Nothing here is looked up in a table of equivalents: band and cup are computed once from the metric ladder, then printed in each system’s own letters (formula version 2).

  • en.wikipedia.org the underbust ladder in 5 cm steps and the AA–H cup table
  • en.wikipedia.org the British and American cup runs, the French +15 shift, the Italian numbering
  • en.wikipedia.org the "+0" and "+4" methods, sister sizes, measuring upright and leaning forward
  • ru.wikipedia.org the Russian table: the same intervals, the same letters

Checked: no date on record

Where these numbers come from

The band is the underbust rounded to the nearest five centimeters, so 112.5–117.5 cm all round to 115. The cup is how far the bust exceeds that band’s nominal value: 30–32 cm gives this letter, at two centimeters per letter starting at ten. Add them and you get a bust of 145–147 cm.

The cup is measured against the nominal 115, not against the tape. That is what every published chart does, and it is why an underbust at the bottom of this band and one at the top get the same letter despite five centimeters between them. Near a band edge, try the sister size too.

In inches, 115J is an underbust of 44.3–46.3" and a bust of 57.1–57.9". Note that the UK and US band number is not that measurement: 115 cm is 44.3–46.3", and the band is called 50GG because the English notation adds four inches.

One step away

115I, 120J — a letter either side of 115J on this band, and this letter on the neighbouring bands.