Asymmetrical bust adjustments

Having an asymmetrical bust can be the reason someone seeks out a custom bra. For me, this was one of several reasons. During the GBSB 2021, I was fortunate enough to learn some of the industry tips and tricks for tackling this issue employed by bra-making professionals. Below, I’ve noted some useful information I gained, and some methods and techniques I am excited to try.


There are a few ways to address an asymmetrical bust when bra-making. Below were the options given for this particular video:

  • Cookie
  • One cup size smaller
  • Half cup size smaller

Some choices are better than others, which I will explain below. However, all of them can be used for different desired results.


A ‘cookie’ is an insert added to a bra to fill out the missing volume. This will be added to the smaller side to fill out the size of the larger side.

Adjusting cup size

As opposed to a cookie, these adjustments really only work if the breasts are one cup size or less in difference. Also, the adjustments are made right to the cups, rather than having two identical cups and adding an insert. There are two methods to do this, although the full cup size adjustment isn’t necessary recommended.

Half cup size adjustment

If your breasts are one cup size difference, you may want to take the average of the two. Most cups are 1/4″ difference between a full cup, meaning it’s 1/8″ for a half-size. By scaling down a half-size, you are, in theory, taking the average of the two sizes. It is assumed that the volume lost and missing will be negligible, whereas making a cup for the bigger cup would make the volume for the smaller side now too large. This can be done in two ways.

Two different size cups

Some people prefer to make two different size cups, one fitting each breast individually. This is often discouraged, as it often results in an undesired, visible difference in the size of the breasts from the outside of clothes. This method can be done in the same way the half-cup size adjustment is done.

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