Understanding When & How To Use Your Bra Sister Size To Find The Perfect Fit

There is no such thing as universal sizing when clothes shopping. In today's world, a size 4 in one brand can be a size 8 in another - how confusing!

Bra sizing can be even more complicated. It is rare for your cup size, band size and unique breast shape to all correlate exactly into a single number and letter.

This is where a sister size bra chart can be helpful, a sister you'll want to meet! Let us explain.

What is a Bra Sister Size?

Simply stated, sister bra sizes share the same cup volume despite different band numbers and cup letters. The great outcome of this is that you can fit into a few different bra sizes because the cup holds the same "amount of boob"!

Every bra size has four sister sizes. The nearest two sizes to your bra size typically offer the best fit. Here is a trick to remember what your two closest sister bra sizes truly are: sister size up & sister size down.

For example, if your bra size is a 36B...

• Sister size up is 38A - meaning one size larger in your current band size and one letter smaller in your current cup size

• Sister size down is 34C - meaning one size smaller in your current band size and one letter larger in your current cup size

Find Your Sister Size

To maximize the likelihood of finding your perfect bra size, it's important to accurately measure your band and cup sizes. Once you have accurately measured your cup and band size, take a look at the below bra sister size chart to better understand your sister sizes!

Do Sister Sizes really work?

Yes! There is a "but" however... sister bra sizes work well when you're either going up or down by one size.

If you try going up or down two or more sizes then the bra composition and proportions are off, resulting in a poor fit. Remember sister means "similar", not the "same" when it comes to sister bra sizing. This concept is especially helpful if your bra is uncomfortable, doesn't fit under clothes properly, or if a size is unavailable.

Our chart above addresses sizing for when the cups fit, but the band does not. If you are looking to solve the fit issue of the band fitting, but not the cups, then simply keep your band size the same and try on various cup sizes.

If neither your band nor cup fits, start with finding the most comfortable band size for you, the cups will adjust accordingly. Admittingly, this last scenario is a bit trickier and may take additional try-ons!

Statistics show 80% of women are wearing the wrong bra size. You can do this - now you are equipped with more bra sizing knowledge! Keep your sister sizes in mind when choosing the perfect size of Silver Sea Apparel for you and check out our step-by-step guide on how to do this in 2 minutes!