Find your new feel-good bra with the BFF (Best Fit Finder): our Aerie-exclusive way to measure your bra size. Watch Iskra show you how to use it, or follow the steps below. All that matters? Finding the bra that feels best!

Before you start, make sure you’re in a lightly lined bra and a tight top, bodysuit or no top. No push up bras or bulky sweaters for this!

Step 1: Find your band size.

Use “This side first!” on the BFF.  Wrap it around just under your bust, making sure the top of the tape is aligned with the bottom of your bra band.

Step 2: Find your cup size.

Use “This side second!” on the BFF. Wrap this side around the fullest part of your bust, and line up the bottom of the tape with the top of your bra band. In the column where the edge of the tape lands, look for the band size you measured in Step 1. The letter next to it is your cup size, and that’s it! You have your Aerie bra size.

Step 3: Find your sister size.

The BFF also gives you your sister size, aka another size you can try to see if it feels good. To find your sister size, check out the color-coded diagonal boxes extending off of the original size you measured. You can try these sizes for a similar fit to the one that you measured.

Get your BFF here. Need a little extra help? Visit us in stores for a custom, free fitting any time.

See more

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  1. Find Your Fit with the #AerieREAL Bra Guide! «American Eagle Blog

    […] if you’re wondering how to find the bra that feels best and measure your bra size, check out our Best Fit Finder and bra size […]

  2. Lynda

    I have loved aerie for a long time but am now unsure that this is a body positive company. I tried using the bra size chart online and my size doesn’t exist despite being an average size. Aerie seems to use a +4 bra sizing method in order to sell whatever sizes are available in a limited range. I noticed the bra size chart goes only up to “DD” which is very limited. I still love aerie and will continue to shop there, but I hope sizes become more inclusive and that measurements become more accurate because inaccurate measurements and lack of inclusive sizing do nothing for self esteem.

    1. Aerie

      Hi Lynda! Thanks so much for your feedback, and we’re sorry that you had a bad experience with our size chart online. We just added size G & H cups and size 42 bands to our Real Sunnie collection, and we are always working to expand our sizes so that everyone can find something to feel good in at Aerie. If you haven’t already, come see us in stores any time for a free fitting so we can help you find a bra that feels best.

      1. Tayler

        I also have this problem, my band size is 40 inches, which I feel is an average band size, but it seems to be unavailable based on Aerie's bra size chart. The bra size chart ends at 36 inches for band measurements.

        1. Aerie

          Hi Tayler, we do have size 40 band! You can shop this size now at

  3. Kiahna

    I am 17 years old and have boobs a little to big for my body. My band size is 32 but my cup size is around 45. Sounds impossible and obnoxious. I struggle finding bras constantly. They are either to big in the band or to small in the cup, i have yet to find a bra from your company that even comes close to a bra that i can wear. Sadly there isn't much you can do. but i wanted to say this because I know there is at least one person out there who struggles with the ratio of band to cup. i just wanted to make it known that my body type exists.

    1. Riley Spotswood

      Same Kiahna! I measure at a 32G and it's impossible to find my size anywhere. I would love to find a bra that fits and that I actually enjoy wearing.

  4. mackenzie marrocco

    I used the AERIE method to find my bra size. I measured 36 inches for bust measurement and 32 for my band measurement. I did not see a size on the chart to match my measurements. What size would this put me at?

  5. Hailey

    I used the best fit finder twice, once with nothing on and once with a sports bra on, both times I got a 40 as my band size but the first time with no bra on I got a D as my cup size and the second time I got a B. I am someone who still has some spillage in an XL sports bra depending on the brand and a DDD from Victoria Secret is too small for me. Just wondering how in the world I could be a D or a B cup.

    1. Aerie

      Hi Hailey, it seems as though the difference is coming from you measuring two different ways (with a sports bra on, and without). We encourage you to try them both and see which you feel best in!

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