How to Measure Bra Size at Home: A Simple Guide

Figuring out the right bra size has always been a complicated task — and in the age of online shopping, it can be even more bewildering. But with the right tools and tips, you can get your cup and band measurements and confidently purchase a bra that fits, feels good, and looks great (with or without clothes on top).

Keep scrolling for helpful pointers and step-by-step guidance on how to measure your bra size at home.

Understanding the importance of accurate bra measurements

According to research, roughly 80% of women wear the wrong bra size, most often one that's too small. This isn't good.

Wearing an ill-fitting bra can be uncomfortable, especially one that's too tight or digs into your skin. Other research suggests that the wrong-size bra could affect posture and potentially contribute to pain or strain for those with larger breasts.

Beyond how a bra feels, the right size will simply look better underneath clothes, with less bulging, puckering, or weird lines from the folds of excess fabric.

Tools you need to measure bra size at home

You need a soft measuring tape (rather than a rigid one) that can wrap smoothly around your body. Aside from that, you don't need much to measure your bra size-- but it might also be helpful to have a large mirror to make sure you're holding the tape at the right angle.

In the privacy of your own home, it's generally best to take the measurements when you're not wearing a bra or shirt. However, you can wear a very lightly lined bra (like a mesh bralette) or a thin t-shirt during your bra fitting that doesn't compress your breasts at all.

Step-by-step guide to measuring your bra size

There are just three main steps in bra measurement to figure out your correct size:

• Measure your band size
• Measure your bust size
• Calculate your bra size

We'll break these down in more detail below.

Step 1: measure your band size

Your band size is the circumference of your body (all the way around in a loop), just below your breasts. It's the upper part of your rib cage in the front and about the midpoint of your back (where the horizontal band of a bra sits).

To get your band size, start by standing upright with good posture. Wrap the tape measure around your back and underneath your bust, making sure it's even on all sides (not lower or higher in the front or back). This can be tricky to do yourself while maintaining a straight posture — if needed, recruit help from someone you're comfortable with.

The tape measure should be touching your skin but not so tight that it digs in. Once it's in the proper position, record the measurement in inches. That number is your band size.

(Band sizes typically range from 28 to 42, but it can go to 50 or higher and varies among brands.)

Step 2: measure your bust size

Your bust size is the circumference of your body around the fullest part of your chest. Getting this measurement is essentially the same as measuring your band size, only a few inches higher.

To get your bust size, stand upright with good posture. Then, wrap the measuring tape in a loop around your back and breasts, ensuring it's not lower or higher on either side. The tape measure shouldn't be tight whatsoever — you'll want to hold it so it's not pressing in or changing the horizontal distance of how your breasts naturally fall.

Record the number in inches. This number will be calculated in the next step to get your bra cup size.

Again, this can be hard to do by yourself. Consider asking a friend or family member for an extra hand.

Step 3: calculate your bra size

To calculate your cup size, subtract your bust measurement number from your band measurement number. For instance, if your band number is 38 and your bust number is 41, you'd subtract 38 from 41:

41 (bust) – 38 (band) = 3 (correlates with bra cup size)

Then you can use that number with a bra sizing chart like the one below to get your letter cup size.

Using the example above, the bra size would be 38C.

The letters can continue to larger cup sizes, sometimes going up to K. Many brands don't have E or I bra sizes, but some do. Other bra makers may not include DD, in which case the number 5 would correspond with F. And some may include D, DD, and DDD.

Your best bet is to have your measurements and numbers ready, then check the brand's bra size chart before ordering anything.

Common mistakes to avoid when measuring at home

As noted, positioning the tape measure just right is crucial for measuring your bra size. It needs to be the same height all the way around your body and not too high or low, just like the horizontal band of a bra.

When measuring your bust size, make sure you're not pulling the tape too tight, as this could result in a lower number and ultimately lead you to purchase (or unknowingly wear) a bra that's too small.

If you're shopping for bras from a brand based in the United States, the measurements will usually be in inches. But for companies in Europe and most other parts of the world, you might use centimeters or a bra-size calculator that converts the numbers for you.

International size charts — and even many based in the U.S. — might differ in other ways, so always check before buying.

When to re-measure your bra size

Measuring your bra size isn't a one-and-done thing you can do once in your life and never have to do it again.

You may want to check your measurements and recalculate your size if you've gone through weight changes or during and after pregnancy. The same goes for your shoe size, which can change slightly, even into adulthood.

If you've been measured in the past but aren't comfortable in your bras, feel like you're spilling out or not filling up the cups, or just think you have an ill-fitting bra, it's always worth re-measuring.

Choosing the right bra once you know your size

Knowing how to measure bra size at home is one thing — knowing what to do with those numbers when it comes to buying a bra is another.

Typical underwire bra sizes feature a number followed by a letter. The number is your band size, and the letter is your cup size.

But what about bralettes and other styles that use shirt sizes, like XS through 3X? In that case, a sister size chart should tell you what size to get based on your standard bra size. For instance, if you're a 38C, you might need to get a size XL (large) bralette.

Negative Underwear now uses numbers for non-wired bras, which convert like this:

• XS = 0
• S = 1
• M = 2
• L = 3
• XL = 4
• XXL = 5

So if you're a 38C and get one of our bralettes, you'd order size 4.

Also, like sports bras, wire-free bra sizing is partly a matter of personal preference. For example, if you're in between sizes and want more give, you can size up.

Explore our bra collections

Negative Underwear is all about maximum comfort, which starts with knowing your size. Once you have that, you can explore our bra collections, and rest assured, you'll never be uncomfortable in a bra again.

Check out our selection of wireless bras, underwire bras, DDD–G cup bras, and nursing bras, or shop best-sellers to see what's most popular. Every style can be paired with multiple cuts of complementing minimalist underwear, from high-rise briefs and mesh thongs to boy shorts and bikinis.

All Negative Underwear pieces are uncomplicated yet luxurious and intimately considered. You might say wearing our undergarments is better than being naked.

Shop by fit

Shop the Negative Underwear bra collection by size, style, color, or material. You can choose bras from bralettes, wired, and non-wired bras with different levels of support, ranging from 32A through G and 0 through 5+.

Final tips for ensuring the perfect fit

Once you receive your bra, try it on as soon as possible. With a brand-new bra, you'll usually want to start with the loosest hook-and-eye setting on the band. The elastic will stretch and relax with continued wear and washing, and you can eventually use a tighter setting. Learn more about how long bras last in order to maintain the best fit for your collection.

Next, adjust the shoulder straps so they're taut and snug (never digging, sagging, or falling off). This will ensure they stay in place while providing the best bust support.

Once the bra straps and band are in place, use your hands to literally scoop your breasts within the bra so they're situated in the center of the cups and on top of the underwire.

If the fit doesn't seem right after trying it on and adjusting everything, don't be afraid to make a return and try again.

Returns are easy with Negative Underwear, and we're always here to help you get the right size or style for your body and breast shape.