Skip to Content

Bra Size Calculator (Beta)

Bras are sized by both chest measurement (in inches) and cup size (in letters); thus, a 38B bra is designed to fit a person who is 38" around the chest with a B cup. We'll get to cup size in a minute.

By the way, when you go shopping, you'll find that many bras will be labelled in three systems of sizing: US, UK and European. We're talking about the US system here. But we digress.

You need to take two measurements: chest and bust, as shown here. Take them without a top on. If you wear a bra, we suggest you unfasten it so its tightness doesn't distort the measurements. It's easiest if you have a friend help. A cloth measuring tape is best.

Take your Chest measurement. Make very sure you keep the tape horizontal and position it just under the bottom of your breasts (or where your breasts will be), as shown here. Note that the calculator will add two inches to account for the extra tissue that most women have at the sides of their breasts that men don't have. The extra space allows you to simulate this with your breast forms for a more realistic shape.

Take your Bust measurement. If you have breast forms, put them on with a comfortable bra, or temporarily hold them in place as accurately as possible with tape. Measure around the fullest part of the breast, again keeping the tape horizontal.

Enter these two numbers in the spaces below to see your bra size!

Chest Size:

Enter your chest measurement here
Bust Size:

Enter your bust size here
Your bra size:

This is US sizing and is only approximate

Disclaimer: These sizes are only approximate and should be used only as a suggested starting point. Body shapes and proportions will greatly affect your actual size and fit. Bra sizes vary between manufacturers and even between styles. Do not use this calculator for non-returnable purchases.

Disclaimer 2: This calculator uses beta software. It is still being tested and debugged and results may not always be what you expect. If you find errors or have comments on it, please email them to .


Bra Sizing

While your calculator did not work as I had wished, it did make me realize the importance of measuring. Surprisingly I was able to find a cloth type measuring tape from Sears today which helped me measure myself as close to possible.

My goodness, was I ever way off in what size bra I could comfortably wear. I had somehow thought that I was a 34B when in actual fact it turns out that I am a 38A!!!!

Thank you so much for stressing the importance of measuring.


What fools these mortals be.
-- Lucius Annaeus Seneca