Bra size calculator

How to measure your own bra size.


Bra measurements

Step 1

Measure your frame size

First, measure your torso (in inches). Place the measuring tape below the underwire, directly under where your bust finishes, right across your back. Take that value and add 4 if it’s an even number, and 5 if it’s and odd number. For example, if your frame measurement equals 30, add 4, for a total of 34. If your frame is a  29, add 5 and your frame is 34.

Bra measurements

Step 2

Measure your bust size

Then measure your bust across the apex, which is the strongest part of your bust, where your nipples are. Make sure the tape measure is straight across your back. This will give you a larger measurement than your torso.

Step 3

Find your cup size

For every inch that differs between your torso measurement and your bust measurement, you add a cup size. For example, if your torso measurement is 30  (giving you a size 34), and your bust measurement is a 34, then every additional inch from 30 to 34 equals your cup size. Therefore, the first inch is an A, the second inch is a B, the third is a C and then a D. So, a frame that has a 30 torso with a 34 bust equals a 34D bra size.

One comment on “Bra size calculator

  1. This calculator is using outdated and incorrect fitting methods! Firstly, adding inches to the bust is wrong, and will put someone in two band sizes too large and two cup volumes too small, originating from a time when bra sizes were measured differently (the band size was your bust measurement). Your underbust measurement IS your band size! If you measure 28 inches, you are a 28 band. The example person is a 30 band.

    For most women without particularly pendulous bresats, a bust measurement taken whilst leaning over at 90 degrees is the most accurate. Take your leaning bust measurement away from your underbust measurement, and you have your cup size.


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