Reviewed by 
Every bra-wearer knows the feeling. You walk in your front door after a long day and the first order of business is to immediately whip off your bra before you even step over the threshold. But it turns out, that's actually not how bras are supposed to make you feel — and if it is, you may be wearing the wrong fit.
A well-fitting bra can be so comfortable that you hardly notice you're wearing it (seriously). And on the flip side, an ill-fitting bra that gapes, slips, rides up your back or digs into your back and ribs is quite possibly one of the most irritating feelings in the world.
Finding the right fit is so important to find the best bra for you. Of course, you can head to a store to get measured for a bra by the pros, but for many, that idea sounds... less than ideal. That's why we spoke with bra experts, including lingerie designers and our clothing experts in the Good Housekeeping Institute, to learn how to measure your bra size at home without setting foot inside a fitting room.
Jump to:
First, here's how to tell if your bra doesn't fit
- Your band is riding up your back. A band that's sitting high, even on the tightest hook, means it's stretched out or too loose. One of the most common mistakes is having the band be too large, and the cups too small.
- Your cups are digging into your breasts. If your breast tissue is spilling out of the cups and you can see a "double boob" in tight-fitting shirts, your cups are too small.
- Your cups gape, or you shift out of your cups as you move. This means your cups are too large (or the wrong shape) for your breasts.
- Your straps keep slipping. If, no matter how many times you tighten them, your straps keep falling off your shoulders, they've lost their elasticity.
- Your bra is showing visible signs of wear. If the underwire has poked through the fabric or if the edges straps are frayed and worn, it's time for a new bra.
How to find your bra size with a measuring tape
You should be measuring your bra size yearly to ensure full comfort in your underpinnings. Here's how:
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, associate director of the Good Housekeeping Institute Textiles Lab. That number is your band size.
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).
Step 2: Measure your bust
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 and bra size
Subtract your band size from your bust measurement to find your cup size. The difference in inches corresponds to your cup size; 1 inch is an A cup, 2 inches is a B, etc. For example, if your bust measures 37 inches and your band size is 34, the difference will be 3, which 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, you'll want to be sure that your string is level and isn't too snug around your back and bust.
Bra size chart
How to know if your bra fits correctly
Acing the right fit should look and feel like this:
- 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.
- The bra stays in place when you raise your arms. If the bra doesn't budge, then you have found a good fit for you.
What about 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.
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 best and feels the most comfortable.
Here are some tips to ID your breast shape:
- Round breasts carry fullness all over. For full breasts, our experts recommend triangle or plunge bras that hug breasts without digging in.
- Teardrop breasts mostly carry fullness on the bottom. Try sweetheart demi silhouettes or fabric overlays that keep cups laying flat.
- Compact breasts sit high, and you might find that bras sit away from your body or that lace or fabric doesn’t lie flat. Shop for stretch fabrics or bras with contoured padding.
- Wide-set breasts carry fullness on the sides. Look for bras with gently curving underwires and generously spaced gores (the center part of the bra between cups).
- Asymmetric breasts are different sizes. Look for stretchy, shallow cups or contour styles sized to the larger breast. (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.
Shop the right bra for your breast shape
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. 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."
"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.
The below chart makes easy work of finding your sister size:
How to make your bras last as long as possible
- Wash your bra only every few wears. "The more you wear and wash your bra, the faster it'll lose its elasticity," says Lexie Sachs, a textiles expert in the Good Housekeeping Institute. "You need that stretch to give you support."
- Keep a few bras in regular rotation. "The more bras you have, the longer you can go between washes," says Danielle Iserlis, former spokesperson for Journelle lingerie. "I personally recommend owning about five everyday bras that you can wear to work," says Seymour. "Then, it's helpful to own a strapless bra, bralette, backless bra or sticky bra to go with more challenging items in your wardrobe."
- Start wearing the bra on the loosest band hook. "That way, you can tighten it as the band naturally stretches over time," says Ra’el Cohen, co-founder and chief creative officer at lingerie brand ThirdLove.
Jessica (she/her) is the director of editorial commerce and product reviews with over a decade of experience as a product tester, reviewer, writer and editor of beauty and lifestyle content. Previously she was the 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.
Emma Seymour (she/her) is the associate director of 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.
