Japanese bra size, explained: Your Japanese bra fitting guide

Posted on 21 November 2019


Love the fun and frills of Japanese bras but completely lost when it comes to sizes? You’re not alone. We’ve come across many customers in the U.S. have a hard time converting their U.S. bra size to Japanese bra size. Is the American B cup the same as the Japanese B cup? Why is a 34 in. converted to a 75 cm when it’s equivalent to 86 cm? The fact is, bra size conversion isn’t so simple. But learn these key differences in Japanese vs. American bras to make your bra shopping a whole lot easier.


American vs. Japanese bras: Band size measurement

A popular U.S. lingerie brand measures the band size by bringing the measuring tape from around your back at band level, under each arm and around the front. The measuring tape rests just above your breast, where the straps meet the top of the cup.

Japanese band size measurement   vs   American band size measurement


On the other hand, most Japanese brands measure band size by bringing the measuring tape from the back band and around under the breasts, keeping the measuring tape parallel to the floor.

Here’s a more detailed reference of Japanese band size measurement.

Now you see why the U.S. band size to Japanese band size isn’t going to be a simple conversion of inches to cm? Because American band size is measured in this way, it will most likely be a greater number than your Japanese band size.

American vs. Japanese bras: Design and padding

Japanese bra styles tend to have smaller cups with thicker padding compared to U.S. styles. Besides the difference in market preference, there’s also a fundamental difference in how our bodies are structured.

Each brand designs their bras to fit the average body structure of the women in the market. Although not all apply, most Asian women tend to have a slimmer and an oval-shaped torso compared to Western women. Asian women also tend to have thinner skin, which is the reason why the fabric and padding in the cups need to be thicker for better support. So, even if you’re wearing the Japanese “equivalent” size bra, it may feel a lot different.

U.S. to Japanese Bra Size Conversion Chart

Now that you’ve learned the difference, put them aside and worry no more! We’ve created our original size & fit conversion guide. This chart reflects our experience of measuring and talking to our customers who’ve visited our stores in LA.

*This size chart is based on the results of measurements made by our company, and will vary with the information on the paper product tags.

Band Size 65cm(30")
JAPAN Bust Size(inch) Bust Size(cm) U.S.Size
A65 29.5" 75cm  
B65 30.7" 78cm 30A
C65 31.4" 80cm 30B
D65 32.6" 83cm 30C
E65 33.4" 85cm 30D
F65 34.6" 88cm 30E/DD
G65 35.4" 90cm 30F/DDD
H65 36.6" 93cm 30G
Band Size 70cm(32")
JAPAN Bust Size(inch) Bust Size(cm) U.S.Size
A70 31.4" 80cm  
B70 32.6" 83cm 32A
C70 33.4" 85cm 32B
D70 34.6" 88cm 32C
E70 35.4" 90cm 32D
F70 36.6" 93cm 32E/DD
G70 37.4" 95cm 32F/DDD
H70 38.5" 98cm 32G
Band Size 75cm(34")
JAPAN Bust Size(inch) Bust Size(cm) U.S.Size
A75 33.4" 85cm  
B75 34.6" 88cm 34A
C75 35.4" 90cm 34B
D75 36.6" 93cm 34C
E75 37.4" 95cm 34D
F75 38.5" 98cm 34E/DD
G75 39.3" 100cm 34F/DDD
H75 40.5" 103cm 34G
Band Size 80cm(36")
JAPAN Bust Size(inch) Bust Size(cm) U.S.Size
A80 35.4" 90cm  
B80 36.6" 93cm 36A
C80 37.4" 95cm 36B
D80 38.5" 98cm 36C
E80 39.3" 100cm 36D
F80 40.5" 103cm 36E/DD
G80 41.3" 105cm 36F/DDD
H80 42.5" 108cm 36G

Bra Size Conversion Chart: Size & Fit

Our two cents on bra sizing

If you’re an American D cup or below, we recommend one of the following:

1. Choose 1 cup above your American size.
2. Choose the same cup size, but go 1 band size above your American size.

If you’re an American E cup or above:

Go up 2 cup sizes from your American size.

If you feel like you particularly have thin skin:


You might want to go up 2 cup sizes even if you’re under a D cup.

When in doubt:

Go up 2 cup sizes from your American size. Especially if you’re getting the “Chomori Maximum Boost Bra”, the pad is thicker than our normal bras, so the bra might feel a lot smaller than your normal American bra.

Now, we all know nothing is guaranteed in life and you’ll need to do a bit of experimenting in the beginning until you’ve found the right fit. But we hope this bra fitting guide cleared up some of the uncertainty you had when shopping Japanese bras.

Aimerfeel is a lingerie and lifestyle brand specifically made to fit Asian women. We’ve been listening to our customers like you and reflecting your opinions into our product development — Ever since our launch in Japan 30 years ago. If you’re in the U.S. or any other country and feel like the bra isn’t fitting you right, come and try out our bras!

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