How to figure out your actual bra size, according to experts

Finding a bra can be difficult, especially one that fits you well in a style you also like.

There are so many variables to account for: band length, cup size and shape, strap length, width, and position, not to mention changing bodies, curves, time of the month, time of the year, occasions, fabric, underwires, lace. Plus, with countless styles and silhouettes, it can be hard to know what feels right until you’re wearing it.

That said, most bra wearers have a size they selected at some point in the past, and unless they've experienced a major body change like pregnancy or weight fluctuation, they've stuck with it. But this may not be the best call, especially if you find yourself frustrated by straps that fall from your shoulders or uncomfortable with too-tight bands or wires that dig in.

“The most common mistake made when choosing bras is that women buy too big of a band size and too small of a cup,” says Christina Faraj Savarese of The Bra Fit Expert in New York.

To help you find the right fit, we tapped advice from bra fit professionals and found the best sizing service from Wacoal.

This is how a bra should fit

Many of us are unaware of what to look for when trying to find the right bra—and it doesn't help that bra sizes vary by brand, explains Lacey Odoms of Lace of Love in New Orleans. She notes that sizes, like most clothing, aren't standardized across retailers. Not only that, but many popular places to buy lingerie have limited offerings.

Miryha Fantegrossi from Wacoal emphasizes that it’s not only your size, but also your breast shape that matters. In other words, the size you've been wearing forever may not be the size that suits your body, or your breast shape, best.

So, how should a bra fit? Wacoal uses 5 Points of Fit—band, straps, cup, shape, and lift—to determine if a bra is right for you.

Band: The band should feel snug but not tight when secured on the first row of hooks. When you raise your arms, the band should also stay in place. About 70% of a bra’s support comes from the band, so it is crucial that it doesn’t ride up or cause pinching or bulging.

Straps: No more than two fingers should fit under the straps (it’s often the easiest fit issue to remedy, as most are adjustable). Since most of the support comes from the band, straps don’t need to be as tight as you might think.

Cup: As for cup fit, your breasts should be completely contained in the cups without any gapping or spillage, and the centerpiece between the cups should fit flush with your sternum.

Shape: We’ve all heard of or experienced the dreaded uni-boob, but spilling out of the side of your bra is just as bad. When trying on a bra, make sure your breasts don’t extend beyond your natural frame. If you’re experiencing side spillage, try a bra with smoothing side support.

Lift: The most comfortable bras lift your breasts up and away from your body. Stand sideways and bend your elbows. The fullest part of your breasts should fall midway between your shoulder and bent elbow.

How to measure bra size

Measuring yourself with a measuring tape at home is a good place to start when determining your correct bra size.

You'll need to take two circumferences—one around your rib cage where the band will sit and one around your breasts at the fullest point. It’s important to not hold your breath and to breathe normally for the most accurate results.

Keep the tape snug without squeezing your ribcage or flattening your breasts. Your ribcage measurement will be your band size. If you get an odd number, round up one, as bands come in even increments.

Have a looser touch with the tape when going around the bust. To find your cup size, subtract your band size from your bust size. Each inch correlates to a letter for the cup. For example, if your rib cage measures 32 and your bust is 35, the 3-inch difference would indicate a C cup.

If all that math isn’t your thing, Wacoal offers a convenient calculator where you can just input your numbers and it will do the math for you.

All of that said, with the variations in bra style and brand sizing, your at-home math is just a starting point. The very best way to find bras that fit you and feel great is to understand your breast shape, chat with a fit expert, or try Wacoal’s mybraFit tool.

Pendulous or round? These are our favorite bras by breast shape

Once you understand your breast shape, you’ll have a better understanding of which styles will offer you the most support and coverage. Here are some of our favorite options for each shape.

Round

Shallow top/full bottom

East/West

Pendulous

Asymmetric