Tested by 
Everyone who wears a bra knows that amazing feeling that they experience at the end of the day, when you get home from work and can finally do yourself the favor of whipping it off. But what if we told you that there is a way to make the experience of wearing a bra less constricting by ensuring that each one you own gives you the most comfortable fit each time? We know, it sounds too good to be true. But in reality, a lot of the discomfort and annoyance that comes from wearing a bra can be boiled down to one thing: you’re wearing the wrong size.
To rid yourself of ill-fitting bras that gape at your bust or ride up your back, it’s important to know how to find your right size. This way, you never have to wait to visit a store when you want a strapless bra, wireless bra, sports bra — or, when you're needing the best large bust or small bust options.
You’ll also save yourself from holding on to bras well past the supportive days. You know, when the straps no longer seem to stay up and the band is too stretched out to fit securely (even on its tightest hook).
But where to get started? Just look at these helpful tips on how to measure your bra size at home from clothing experts in the Good Housekeeping Institute, and then get ready to find the best bra for your body.
FYI: You should be measuring your bra size yearly! "This can help you celebrate the body you have and ensure full comfort in your underpinnings," says Danielle Iserlis, former associate marketing manager at Journelle. It will also help indicate whether or not it is time to find a new bra.
How to find your bra size with a measuring tape
Step 1: Find your bra band size
Wearing an unlined, non-padded bra (not over your clothes!) or a fitted t-shirt, run the measuring tape all the way around your back where your band sits, being careful to keep the tape level. "Take a couple deep breaths and make sure the band isn't too snug — you should be able to comfortably fit two fingers beneath the tape measure," says Emma Seymour, senior product analyst at the Good Housekeeping Institute Textiles Lab. If you don't get a whole number (e.g. 33 and 1/2 inches), or you get an odd number that's between traditional band sizes (e.g. 33 inches), round up to the nearest whole, even number (34 inches). That number is your band size.
Step 2: Measure your bust
To measure your bust, says Iserlis, “run the measuring tape around your back, just under your shoulder blades, and up around the fullest part of your bust. The tape should just skim the bra in front.”
Step 3: Calculate to find your cup size
If you're still wondering: "What is my cup size?" All you need to do is a little bra math: Subtract your band size from your bust measurement to find your cup size. “The difference in inches corresponds to your cup size,” says Iserlis. For example, if your bust measures 37 inches, and your band size is 34, the difference will be 3. On the chart below, you'll see a 3 is equal to a C cup, meaning your bra size is 34C.
How to find your bra size without a measuring tape
No measuring tape? No problem! You can easily measure yourself with a household item like "a piece of string or ribbon (just make sure it’s not stretchy!)," says Seymour. "Then, measure your bust and band sizes with the string, and then you can measure the length of the ribbon with a ruler." As with the measuring tape though, you'll want to be sure that your string is level and isn't too snug around your back and bust.
Bra measurement FAQs
How to find the right bra for your breast shape
Just because you've found your correct bra size (yay!) doesn't mean your work is done (sorry!). If you're not finding the perfect fit even after measuring yourself, you might be missing an important piece of context: your breast shape. “Even if you’re wearing the ‘correct’ size, it might be that you’re wearing the wrong bra for your shape,” says Iserlis.
Fit is dictated as much by size as it is by breast shape, so you shouldn't be afraid to try additional sizes from various brands to find the bra that looks the most flattering and feels the most comfortable. "Keep in mind, as with all clothing, different brands will fit you differently," says Lexie Sachs, executive director at the Good Housekeeping Institute Textiles Lab. "Not all 34Bs are created equal," points out Iserlis.
Some rules of thumb:
- If you have full, round breasts, you carry fullness all over. For full breasts, our experts recommend triangle or plunge bras that hug breasts without digging in, like Hanes Ultimate T-Shirt Bra.
- If you have teardrop breasts, you mostly carry your fullness on the bottom. Iserlis suggests sweetheart demi silhouettes or fabric overlays that keep cups lying flat, like Wacoal's Elevated Allure Underwire Bra.
- If you have compact breasts, your breasts sit high, and you might find that bras "sit away from your body or that lace or fabric doesn’t lie flat,” says Iserlis. Shop for stretch fabrics or bras with contoured padding, like Natori's Pure Luxe Bra.
- If you have wide-set breasts, you carry your fullness on the sides. Look for bras with gently curving underwires and generously spaced gores (the center part of the bra between cups), like the Freya Idol Moulded Balcony Bra.
- If you have asymmetric breasts, one breast may be larger than the other. This is “very common to all women in the world,” says Iserlis. Look for stretchy, shallow cups or “contour styles sized to the larger breast,” she suggests. (Hint: Always shop for the larger breast to avoid telltale spillover.) You can also shop for bras with removable padding to compensate for the smaller side, like ThirdLove's 24/7 Classic Contour Plunge Bra.
Shop the right bra for your breast shape
SPANX Bra-Llelujah Full Coverage Bra
How to know if your bra fits correctly
- The band sits level all the way around your ribcage without riding up, constricting, or squeezing.
- The center of the bra lays completely flat against the breastbone. That center piece between the cups is called the gore, and it shouldn't hover above the chest.
- The straps fit snugly without digging in. They should be adjusted to fit tightly enough for support, but not so tight that they dig in. Indentations or tired shoulders are a sign they're too tight.
- The cups don't gape or dig into the breasts, even when you move around. Be sure to walk, dance and wiggle around a bit to see how your breasts settle into the cups, and check both the sides and the front for potential spillage.
- "Lastly, raise your arms," says Fantegrossi. "If the bra stays in place, then you have found a good fit for you."
What is a bra "sister size"?
If you've measured meticulously, shopped for your breast shape and your bra still isn't fitting perfectly, you might need to shift your sizing a bit. "A sister size refers to a bra size that has the same cup capacity with a different band size," says Seymour. "You should opt for a sister size when the cups fit but the band doesn’t," she advises.
For example, if you try on a bra and the cups fit but the band is too tight, you can't just go up a band size: "You’ll actually end up with larger cups if you do this," Seymour explains. "Choose a sister size instead with a larger band for a better fit." The below chart makes easy work of finding your sister size:
Jessica (she/her) is a deputy editor at the Good Housekeeping Institute and a longtime product tester, reviewer, writer and editor of beauty and lifestyle content. She has over a decade of industry experience, previously as beauty editor at USA Today's Reviewed where she launched the Beauty vertical and tested hundreds of products and has covered trends for publications like The Boston Globe and The New York Times. You can usually find her sorting through piles of beauty products — and testing the best ones on camera.
Cameron (she/her) is a staff writer for Good Housekeeping, where she covers everything from holidays to food. She is a graduate of Syracuse University, where she received a B.A. in magazine journalism. In her spare-time she can be found scrolling TikTok for the latest cleaning hacks and restaurant openings, binge-watching seasons of Project Runway or online shopping.
Emma Seymour (she/her) is a senior product analyst at the Good Housekeeping Institute's Textiles, Paper and Apparel Lab, where she has led testing for luggage, pillows, towels, tampons and more since 2018. She graduated from Cornell University with a bachelor of science in fiber science and apparel design and a minor in gerontology, completing research in the Body Scanner Lab on optimizing activewear for athletic performance.
