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Japanese sizing · cup letter first

B70 Bra Size, In Full

A Japanese B70 is a 70 cm band with a B cup: written cup-first, measured in 2.5 cm steps, and one letter ahead of the Western alphabet. In US terms this body wears a 32A.

The numbers

B70 measurements

Underbust≈ 70 cm (67.5–72.5)
Top bust≈ 82.5 cm
Difference≈ 12.5 cm → JP B
NotationCup first: B70, not 70B
The trap

A Japanese B is not a Western B

Japanese cup labels start earlier and step in 2.5 cm increments, so each letter sits roughly one label ahead of its Western namesake: this B70 corresponds to a US 32A and EU 70A. Order your Japanese letter from a Western shop (or vice versa) and you’re a full cup off before the parcel ships. The converter translates in both directions.

US32A
UK32A
EU / DE70A
FR / ES85A
IT2A
AU / NZ10A

Bands translate cleanly (same centimeters as EU labels); only the letters shift.

Same volume, different band

B70 sister sizes

Snugger band, same volumeC65
Looser band, same volumeA75

Japanese sisters move in 5 cm band steps with one cup letter, same volume, different circumference. Useful when domestic stock stops one band short of yours.

Construction

What works at this size

At this volume nearly every style in Japanese ranges works, and Japanese ranges lean heavily on molded, lightly padded cups with soft wires. Choose by neckline; construction rarely limits you here.

Neighbors

Related Japanese sizes

Same band (70), other cups

Same cup (B), other bands

Answered

B70: answered

What is Japanese B70 in US sizing?

US 32A (UK 32A). Japanese cup letters sit one label ahead of Western ones for the same body (a Japanese B corresponds to a Western A-tier cup) so carrying the letter across unconverted buys a cup too big.

What measurements is B70 for?

An underbust around 70 cm (roughly 67.5–72.5 cm) and a top bust near 82.5 cm: a difference of about 12.5 cm, which Japanese sizing labels B. Japan measures in 2.5 cm cup steps against Europe's 2 cm, so conversions are nearest-label, not exact.

Why is the cup letter written first in B70?

Japanese convention writes cup-then-band. C70, not 70C. Same information, reversed order; on tags in Japan you may also see the band alone (70) with the cup on a separate line.

Shop itAt HauteFlair, our sister retailer

HauteFlair labels cups in UK letters, so these links already convert your size by position (a US DDD lands on a UK E, a US G on a UK F). HauteFlair is owned by the same company as Brasize.ai; that relationship never changes the sizing math, charts, or fit advice on this page. How this site makes money.

Start from the measured size

Two measurements, no inches added, sister sizes attached.

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