Sister sizing is a concept in bra fitting that helps you find alternative bra sizes that offer a similar fit when your regular size isn’t quite right or isn’t available. Understanding how sister sizes work can be particularly useful when you're struggling to find a comfortable fit or when shopping for bras from different brands. Here's how sister sizing works:

Understanding Sister Sizes

Basic Concept:

• Sister sizes are bra sizes that have the same cup volume but different band sizes. When you move to a different band size, the cup letter changes to maintain the same cup volume.

How it Works:

• Down a Band Size: If you go down a band size, you need to go up a cup size to maintain the same cup volume.
• Up a Band Size: If you go up a band size, you need to go down a cup size to keep the same cup volume.

Example of Sister Sizes

Let's say your current bra size is 34C. Here’s how you would find the sister sizes:

• If you go down a band size (to 32):

  • Your new sister size would be 32D. (You go up one cup size to maintain the same cup volume.)

• If you go up a band size (to 36):

  • Your new sister size would be 36B. (You go down one cup size to maintain the same cup volume.)

Sister Size Chart Example

Here’s a quick reference for how sister sizes work with a few examples:

• 30D → 32C → 34B → 36A
• 32B → 34A → 36AA
• 34C → 32D → 36B → 38A
• 36D → 34DD → 38C → 40B

Why Sister Sizing is Useful

1. Finding a Better Fit:

   • If your regular size feels too tight in the band but the cups fit well, you might try the sister size with a larger band and a smaller cup.
   • If the band is too loose but the cups fit, try a sister size with a smaller band and a larger cup.

2. Brand Variations:

   • Different brands may fit slightly differently, so knowing your sister sizes can help you find a better fit across different styles and manufacturers.

3. Limited Availability:

   • If your exact size isn’t available, sister sizes offer alternatives that may still fit well.

Things to Keep in Mind

1. Comfort:

   • Even though sister sizes have the same cup volume, the fit may feel slightly different because of the band size. Always ensure the band feels comfortable and supportive.

2. Try Before You Buy:

   • If possible, try on the sister sizes to ensure they provide the comfort and support you need. The band should sit snugly around your ribcage, and the cups should fully encase your breasts without spilling over or gaping.

3. Strap Adjustment:

   • Adjust the straps as needed when trying on sister sizes, as the position of the straps can shift slightly with different band sizes.

Sister sizing really works for some girls...

Sister sizing allows you to find alternative bra sizes that maintain the same cup volume but have different band sizes. By going up or down a band size and adjusting the cup size accordingly, you can find a comfortable fit even if your usual size isn't working for you. Remember to try on different sister sizes and adjust the straps to ensure the best possible fit and support.