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Macy’s / Ideas & Inspiration / Bra & Lingerie Fit Guide / How Do Bra Sizes Work? - Bra Fit FAQ - Macy’s

How does Bra Sizing Work?

Bra sizes are based on your band size (the number) and your cup size (the letter). These measurements are usually determined by using a tape measure around your rib cage and bust. The number/letter is your bra size. Finding the right bra size is crucial for the right support and for a smooth comfortable fit. To all the girls who have worn an ill-fitting bra or wrong bra size know that this can ruin a great outfit and even worse the entire day with backaches and pain. Here’s the thing, we want to take the stress out of finding the right bra size with Macy’s Bra & Lingerie Guide. We outlined how bra sizes work and how your bra should fit. We also explain what sister sizing is—because that can be tricky! So, whether you’re a 32AA, a 58K or somewhere in between, you’ll find the right bra size at Macy’s. And, we carry all of your favorite brands including Maidenform, Elomi, Chantelle, Wacoal and many more. Finally, bra sizes explained!

How to Measure Your Bra Size?

The best option for determining your bra size is by taking bust measurements using these simple measuring instructions. All you need is a tape measure and a little free time. Remember to grab a pencil and paper to jot them down. And heads up, there will be a little math involved—it’s basic, we promise, so no need to bust out your calculator!

  • Step 1: Take Your Bust Measurement
  • Wrap a measuring tape around the fullest part of your bust (at nipple level). Take a deep breath in and out to ensure the tape isn’t too tight. Round to the nearest whole number.

Pro Tip: If the measurement falls on the half inch, round it up.

  • Step 2: Determine Your Band Size
  • Measure around your torso directly under your bust where the band would naturally sit. The measuring tape should be level and snug. Round to the nearest whole number. If the number is even, add four inches; if the number is odd, add five inches—your band size is the sum of this calculation.

Pro Tip: Did you get an odd number? Just round down to the nearest even number.

  • Step 3: Calculate Your Cup Size
  • To determine your cup size, first subtract your band measurement from your bust measurement and refer to the cup size chart below. For example, let’s say your bust measurement is 40” and your band size is 36” (40” - 36” = 4”). Check the chart below to discover your cup size. In this example, you’re a D cup, so stock up on 36D bras.

Cup Size Conversion Chart

Helpful Hint: Your bra size changes just like your dress size, so you should plan to get a bra fitting at least once a year. Check to see if your local Macy’s store has a fit specialist.

How Should A Bra Fit?

Your bra should feel snug, yet comfortable. How will you know when you’ve found the perfect fit? To make sure a bra size is correct, give it a test with these 7 check points:

  • 1.  Bend at the waist and hook your bra. Your breasts should be completely covered in the cups.
  • 2.  Adjust the band. Be sure the back and front of the bra are level.
  • 3.  Make sure it’s not too loose. You should be able to slide only 1 finger underneath the band.
  • 4.  Fix falling straps. Tighten the band and shorten the straps for a better fit.
  • 5.  Stand sideways in a mirror. Your breasts should sit midway between your shoulders and elbows.
  • 6.  Comfortable fit. If you need to go down a cup size, then go up one band size and vice versa.
  • 7.  Choose the perfect fit on the outermost hook. This way when the bra loosens over time, you can adjust it to the tightest hook.

What are the Common Bra Fit Problems?

There are few telltale signs that you may not be wearing the right bra size from wrinkling in the cups to a bra that hikes up when you lift your arms. Not all bras are created equal. Different brands may run smaller or larger depending on the style. We get that bra size can be confusing, so think of it like jeans shopping. You don’t always wear the same size pants and you would never assume a pair fits without trying it on first. The same is true for bras! Here are some practical tips on how to avoid the ill-fitting, uncomfortable bra:

  • The bra band is too tight. Your bra band should fit snugly around your body, and still allow you to breathe comfortably.
  • The straps dig in. Your straps should not be too tight, and you can always adjust them.
  • The straps are falling down. If your straps are too loose, just adjust them for a better fit.
  • The bra band rises up. Should your bra band be a bit big, fasten your hooks on
    the tightest section.
  • The bra band creates bulges. It should not be too small.
  • The cups are too loose. They should cover your entire bust without any gaps.
  • The cups are too tight. There should not be any spillage from the cups.

Helpful Hint: Various bras may run smaller or larger depending on the brand or style.

What is a Sister Bra Size?

Sister sizing are bra sizes that are grouped in the same family depending on their cup volume. So, if you can’t find a 34C, go for its sister sizes of 36B or 32D. In order to get your sister size, you have to go up a band size and down a cup size. Discover your long-lost sister size in the chart below. Look for your regular bra size on the chart below; the sizes to the left and the right of that size are your sister bra sizes.

Sister Sizing Chart

Are There Bra Size Standards and Conversions?

A bra made by a US brand is sized differently than one made in Europe or the UK, so anything above a D-cup may need to be converted. The band and cup size should be standard. However, each brand can have slight variations in fit. To find your perfect match, you should try on several bras from different brands.

FAQs: Bra Clothing Recommendations

  1. Q: What do you wear with a transparent T-shirt?
    A: A see-though T-shirt requires a nude bra for modesty.

  2. Q: What do you wear with a backless plunge dress?
    A: A backless dress requires an adhesive bra for no-show sexiness.

  3. Q: What do you wear with a strapless dress, strapless top, one-shoulder dress or top?
    A: Your strapless tops and dresses and cold-shoulder looks require a strapless bra for a smooth, sleek look without ugly straps showing up.

What Bra Fit Services Does Macys Offer?

We know there’s more to you than a number and letter. Experience a bra fitting with one of our certified Fit Ambassador at a Macy’s store near you. What are the benefits of a personal bra fitting? The focus is on you and your comfort.

  • Macy’s Fit Ambassadors Measure You ...correctly- step-by-step to determine your correct size.
  • Macy’s Fit Ambassadors Make the Right Recommendations. They pick and show you the right size, right brand—the right solution for your body type.
  • Sister Sizing is No Mystery to Use. We will inform you of your size options—there’s more than one option for your body type!
  • Macy’s Fit Ambassadors are Brand Experts. We know the styles, the fits the difference between the most popular brands to offer you many choices.
  • We’ll Match It. We offer you the matching panty, shapewear or robe, too!
  • Unparalleled Service. Unparalleled Selection...because it’s all about you!

Helpful Hint: How often should you replace your bras? We recommend that you swap out your bras every 6 months. They become less supportive and stretched out over time.