How To Measure Your Bra Size

How To Measure Your Bra Size

Whether or not you wear a bra is a matter of personal choice, but even if you only wear one occasionally, you still need to know how to properly measure your bra size. This will ensure that those you own fit, flatter and offer all the support they’re intended to. 

While a good bra goes completely unnoticed, a bad bra can come between you and a productive day in the library, a great night out, or simply the ability to make your graceful descent down a flight of stairs. Unfortunately, many of us own far too many that fall into the latter category. “It is not uncommon for people to swap between just two bras despite owning between 10 and 20 of them,” explains Kelly Dunmore, chief lingerie stylist at Rigby & Peller

The bra-wearers among us will also know that our preferred style can change due to multiple factors, including — but not exclusive to — our outfit, the time of the month, and as our breasts develop and change in size. So, how to measure for a bra that fits perfectly? We’ve broken down everything you need to do to get the right bra size the first time — and improve the ratio of good to bad bras in your wardrobe.

Where to begin

A common mistake is refusing to consider the possibility that your bra size has changed since the last time you were measured. In addition to the impact of age and lifestyle, your size will likely vary depending on the bra itself. 

But though sizing differs from brand to brand, there are two basic measurements that will guide you regardless: the band size, and the cup size. Many bra-size calculators available online will do the math for you, but if you want to be sure, try the following method…

How to measure your bra band size?

  1. Stand upright without a bra on, and using a measuring tape, measure around your back and under your bust, where the band of a bra would usually sit. 
  2. Make sure the tape is going around in a steady, even line. It should feel snug, but not tight. 
  3. Measure in inches: 
    1. If you land at an even number, that is your band size. 
    2. If it’s an odd number, round it up to the nearest inch to find your size.

How do I work out my cup size?

For this bit, most retailers recommend you wear your current favorite (i.e. most comfortable), bra so that your boobs are held in the place you actually want them to be. 

  1. Then measure around the fullest part of your chest. 
  2. Next, subtract your band size from this bust measurement. The difference denotes your cup size. 
  • 0 = AA
  • 1 = A
  • 2 = B
  • 3 = C
  • 4 = D
  • 5 = DD
  • 6 = F
  • 7 = FF
  • 8 = G
  • 9 = GG
  • 10 = H
  • 11 = HH
  • 12 = J
  • 13 = JJ
  • 14 = K

Combine your band and cup size, so you have a number followed by a letter, for example, 34F. 

This is your benchmark measurement — but remember, there’s a whole lot of nuance involved in finding the perfect fit, like considering your style and fabric preferences.

How do I know if my bra fits properly?

“Once you’ve fully adjusted the garment, you really shouldn’t feel like you’re wearing anything,” explains Miryha Fantegrossi, vice president of merchandising and design at lingerie brand Wacoal. 

  • Start by doing up your bra using the loosest hook. Then adjust the straps so that they are tight, but not digging into your shoulders. 
  • If you look at yourself sideways in a mirror, your breasts should sit midway between your shoulders and elbows. 

The best way to assess the fit: Put on your slinkiest T-shirt: “If you can see any lines or bulging skin, you know it’s not the right size,” explains Emilie Moraes, resident expert at Harvey Nichols.

How do I know if the band is firm enough?

The band provides 80 percent of a bra’s support – so if it’s too loose, it’s not going to hold your breasts in prime position. Instead, it should fit firmly to the body. “You want to [be able to] get three fingers up the back of a bra, and two fingers all the way around,” explains Dunmore. It should be “horizontal around the body, and there shouldn’t be any places where it’s pulling up, dipping down, or uneven,” agrees Cora Harrington, founder and editor-in-chief of The Lingerie Addict.

Don’t be alarmed if it feels too tight at first. “If you’ve been wearing something very loose in the back, and then I put you in something firmer, your body needs time to adjust,” says Dunmore.

Why do my bra straps keep falling down?

“You should be able to slide one finger underneath the strap, but not lift it up,” says Fantegrossi. Adjust them and re-check every three to four times you wear your bra, and always after washing. If you find yourself continually adjusting your straps to lift your bust, revisit your band size. If your straps consistently slide off your shoulders, it might be because your shoulders slope downwards. In this case, move towards a racer-back style. A good rule of thumb is to be refitted every six months.

What if the band is riding up?

If the band is riding up on a new bra, try loosening the straps, or changing to a tighter hook. If that doesn’t work, you will need to go up a band size. Bear in mind that when you increase band size, you might need to go down a cup size (so if your 34C bra is riding up, try a 36B).

Is a bra definitely too tight if it leaves an imprint on your skin?

No. That being said, if you want to avoid it, consider increasing the width of the band at the back.

The cups: how do you avoid spillage?

Spillage usually happens if you’ve reduced your back size (often the right thing to do), or if your boobs aren’t oriented the way your bra wants them to be. Either increase the cup size or look to a wider wire shape for greater containment.

What about gaping cups?

Try tightening the band to cinch the wire under the breast tissue and bring the cup closer to your body. Tightening the straps might also help. If this fails, you will need to go down at least one cup size.

The bridge: does it need to be flat to the body?

The bridge, sometimes called the gore, is the centerpiece of the bra where the two cups join. “In an ideal world, you want that to sit as close to the sternum as possible,” says Dunmore. If it isn’t holding in place, try going down one band size or up a cup size. Alternatively, try a plunge bra, which usually has a narrower center front.

What are the best bras for my shape?

As with any item of clothing, some just fit our individual shapes and preferences better. Those with a fuller bust might prefer to opt for a full cup or balconette bras, which come with thicker straps and more supportive underwiring. While those of us who require smaller sizes might prefer bralette or crop-top styles. Not only are they very comfortable, but they offer just the right amount of support and follow the natural shape of the bust.




Source: Owen, Charlotte, and Naomi Pike. “How To Measure Bra Size: The Vogue Guide | Vogue.” Vogue, Vogue, 1 July 2022,
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