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Is The Cup Half Empty or Half Full?

When we began developing half-cup sizes at ThirdLove, we knew that most women (including ourselves) weren’t happy with the sizing status quo and were wearing bras that just didn't fit them. In fact, we found that 50 percent of our customers between A and E cups are a half-cup size and don’t fit into a standard cup.

Think about that for a second: one in two women don’t fall into a standard cup, yet have been wearing standard cups their entire lives. Before half-cups, the only option was to wear a bra that caused overflow or cup gaping - that’s not good enough. So, we decided to change our products to better fit customer’s needs.

So, we made it our mission to poke holes in current industry sizing and conduct focus groups to glean insights into how to make sizing better and more inclusive to all women’s shapes.

Here’s what we found:

50 percent of women could be happier with how their bras fit.

Since one in every two women between A and E cups don’t fall into a standard cup, we knew right away that if we offered additional cups for these “in betweeners,” we could change the game like no other company had before - and make 50 percent of women much happier with how their current bras fit.

So, how do you know if you’re one of the “in betweeners”? If you’re not quite filling out your current cups, we often recommend trying a half-size smaller. Or, if your cups feel a bit too snug (but aren’t yet cutting off your circulation), a half-size up might do the trick. Spilling over the edge of your cups? You may be wearing a size or half-size too small. If any of these sound like you, consider trying out our iOS app or use the Fit Finder™ at to see what your true size is.

Your bra size can change throughout your life.

This is another reason why half-sizes are so important - even the smallest changes to your body can bump your bra size up or down a size (or half-size). While some people think your bra size is your bra size for life, your size actually changes an average of six times throughout your life.

When it comes to fit, we understand that getting measured in a lingerie or department store is kind of a drag. If your current bra doesn’t fit quite right, we suggest checking out our half-cup sizes and regularly sizing yourself, paying close attention to the different factors that cause your breasts to change, such as weight gain or loss, change workout habits , or have a baby. We offer two easy ways to do this: our iOS app and the Fit Finder™ at Doing these exercises regularly will ensure the best possible bra fit.

In the end, our decision to develop and offer half-cup sizes and hunt for the perfect fit has been a great one. For tens of thousands of women our bras are the first bra they have been able to find that fits perfectly - and we think that’s pretty amazing.

Are you a half-cup? Find out now with our Fit Finder.