Bra Size Calculator

Please Note, this calculator is designed to calculate the size of the bra you need during the first six months of your pregnancy.  It is not designed to calculate the size of your nursing bras or your "normal" size.

When fitting for a "normal" bra you always calculate the size so that the bra fits perfectly on its LOOSEST set of eyelets.  As the bra fabric "relaxes" (due to wear and washing) the bra can be tightened to maintain the correct support from the band.

However, with a bra during pregnancy I always recommend that the bra is sized so that it fits correctly on the TIGHTEST set of eyelets. As the body grows during pregnancy the bra can be loosened so that it does not become too tight.  This is generally a band size larger than the size you would have been measured for a "normal" bra.

However, it is not quite that simple.  I would recommend that although you might go up a back size, that you should keep your physical cup size the same as your "normal size (particularly during the first few months of pregnancy).  If you go up a band size, the cup increases in size as well (ie. a 38D has a larger cup than a 36D). So in order to fit your breasts correctly, you need to go down a cup size from your normal size.

This is just because of the way that bras are sized.   For example, a 36D has the same sized cup as a 38C, a 40B, and a 42A (and so on). So when you go up a back size, you have to go down a cup size - it sounds odd but it is correct.

For example, if your normal size is a 36C, I would recommend (and the calculator will suggest) a 38B.

So, please take your underbust and overbust measurements as they are today and pop them into the calculator.

Note: your underbust is measured snugly around where the band of your bra would sit - the tape should be as tight as your bra band would be.  Your overbust is measured around the fullest part of your bust, with a good fitting bra ON - the tape should be held normally (ie not tight).

Under-bust size (A)



Over-bust size (B)



Now please select your size from the drop down list on the top left of each page