New York City | The Hamptons

How a Bra Should Fit

How to Measure Your Bra Size
Use a tape measure to measure the fullest part of your breast, with a bra on. This helps determine your cup size.

As a New York City board-certified plastic surgeon specializing in cosmetic breast surgery, women see me to talk about breasts—in many cases how they can fix problems with their breasts and feel more confident, overall, about their breasts. But sometimes it doesn’t take surgery to feel better about your breasts. Sometimes all it takes is the right-fitting bra. Understanding how a bra should fit is something every woman should learn—and something that I’m going to highlight here.

The right-fitting bra will instantly make your breasts look better in everything you wear.

I’m continually astonished by how many women are wearing the wrong size bra, which is not only uncomfortable and can be painful, it can also make your breasts look anything but perky and firm. (Women’s Wear Daily reported that 64 percent of women are wearing the wrong bra size.)

I’ve spoken with the bra fit experts at Wacoal. Here are the tips that I give to my patients about how a bra should fit—and about selecting the best-fitting bra for them:

√ Measure your breasts—even if you did it years ago. Most women got measured at some point in a lingerie department. But breasts change—and so does breast size. The reason: Weight gain and loss, pregnancy, hormonal changes, and aging can all affect the size of your breasts over time.

The bra size that worked for you years ago may not work for you today.

To measure your breasts, use a tape measure to size two areas:

a) around your chest and the middle point of your breasts around your areolas (called the fullest part of the breast); you can do this wearing a non-padded bra, and

b) just under your breasts, making sure the tape measure goes around the center of your back, lying flat on the back. (Pull up on your bra straps or hold up your breasts, particularly if you have larger breasts, to get the most accurate measurement.)

The measurement from the fullest part of your breast (the measurement in a) will help determine your cup size. This is the letter part (e.g. 34C or 36B) of your bra size.

The measurement under your breasts and around your back (the measurement in b) will help determine your band or chest size (round up to the nearest even number) and this will be your band/chest size. This is the number part (e.g. 32AA or 34D) of your bra size.

If your friend or a bra fitter tries to pull the band out from your back, she should barely be able to stretch it, if you’re wearing the correct band size.

Remember that the cups attach to the band. If the band is too loose and sliding around, the cups cannot possibly lift and support the breast.

“Always buy a bra that you fit to the loosest hook on the bra. Bras can stretch up to 3 inches over the course of wearing them, so this will ensure you’ll be able to wear the bra longer.”

√ Determine your cup size. Subtract the band/chest size (b) from the size of the fullest part of your breasts (a). This chart helps determine what your cup size is. If the difference between (a) and (b) is:

How to Determine Bra Cup Size


√ Try on different bras; every bra fits differently. This is very important as—after measuring—you may determine that you are a 36C. But when you try on a certain style, the 36C in that style doesn’t fit well. You may have to go down to a 34D to get the perfect fit.

Finding the Perfect Fit

Here’s how a bra should fit:

√ If you’re wearing an underwire bra, the underwire part of the bra should lay flat on your chest without any gaps.

√ Breasts should be contained completely inside the bra and should not bulge out of the sides or the top.

√ When you raise up your arms, the bra should not ride up but should stay firmly against your chest. If the back of your bra rides up, then your band may be too large or you may need to adjust the bra to a tighter hook. (A bra back should sit parallel to the floor on your back.)

√ Straps shouldn’t be digging into your shoulders; this is typically a sign that you need to reduce your band size. Straps shouldn’t slide off your shoulders either; this usually indicates that the bra straps need to be adjusted—or are too wide set, in which case, you may need a different style.

Breasts can look perkier, more shapely and your figure more in proportion with the right size bra. Check your bra size today.

Back to blog