How Big Are B Cup Breasts?

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There is a wide range of bra cup sizes that start from the smallest AA and go all the way to size O. Keeping this in view, it is obvious that the B cups are not very big. But how big are B cups exactly? Let’s find out!

How Big Are B Cups?

The B cups refer to a 2-inch difference between your band and your bust size. This entails that if you have B cups, your breasts will protrude out approximately 2 inches from the chest wall. Consequently, women with a B cup size are said to have small boobs.

B cup bra sizes have a 2-inch size difference between the band and the bust measurements

However, having small breasts does not mean that you cannot flaunt your curves. The right kind of bra can provide you with attractive cleavage and also make your bust appear bigger. You can wear a padded bra to gain some extra volume or a push-up bra to enhance your cleavage.

How Much Does a B Cup Weigh?

Breasts that fit into a B cup bra are not very big. Hence, they do not weigh too much either. In general, a B cup breast will weigh around 0.86 pounds. To give you some perspective, the weight is equal to five cockatiels, which is a very small parrot.   

A wide majority of women prefer to have a larger chest size since bigger boobs are associated with maturity and are perceived as sexy. This is evident by the fact that the most common plastic surgery procedure is breast augmentation or enlargement surgery, according to the American Society of Plastic Surgeons.  

However, these are just opinions perpetuated by the media’s obsession with bigger bosoms. In reality, there is no optimum size for the female bust because breast sizes do not have any bearing on a woman’s breastfeeding ability, fertility, or breast sensitivity. Therefore, it is more important to feel confident than to look a certain way.  

How to Find Your Bra Size

The appearance of your breasts is largely dependent on the type and size of the bra you wear. For B cup breasts, you do not need a lot of support. You just need a well-fitted bra that provides a nice well-defined shape, a little coverage, and some extra padding.

Woman wearing a light green bra

If your bra is too tight, your breast tissues will spill over your cups and the bra will feel restrictive. Contrarily, a loose bra will have a gap between the cups and your breast. Your bra straps will also fail to stay in place and drop down your shoulders. 

Therefore, it is imperative to know your exact bra size that constitutes a number and an alphabet. Below I have outlined the correct way to determine your bra size, so you can make the most of your assets while feeling comfortable in your bra.  

  1. First, place a soft measuring tape right under your breasts on your ribs. Wrap the tape around your torso, making sure it lies straight across your frame until it meets the beginning of the tape. The reading you will get is your band size
  2. Next, take the same tape and wrap it around the largest part of your chest, also known as the bust line. Make sure your arms are down when you note the reading of your bust size.
  3. The cup size is the difference between these readings. So if the difference is 2 inches, that means you have a B cup.

How to Increase Breast Size

While I believe in endorsing body positivity, I am also strong proponent of doing what you can to feel comfortable and confident. Therefore, if your B cups are making you feel self-conscious, there are quite a few ways to increase your breast size and a curvier frame. 

Woman wearing a purple bra

Breast augmentation is a very common way to increase your bust size. However, surgical procedures are costly, invasive, and taxing for your body. Instead, you can focus on working out to achieve a bigger bust. For example, certain yoga poses can stretch and strengthen the breast muscles, to make your breasts appear fuller and perkier.

You can also engage in workouts targeted at the chest region to help you enhance your posture and breast size. These may not have a dramatic result but can take you up a cup size. There are also claims that breast massages can increase blood circulation and ultimately the breast size, but it lacks scientific proof.

Comparing B Cups vs Other Cup Sizes

Cup Description Average Weight
A 1-inch difference between the bust and band0.5 pounds per breast
B 2-inch difference between the bust and band0.86 to 2.36 pounds per breast
C 3-inch difference between the bust and band1.13 to 2.63 pounds per breast
D 4-inch difference between the bust and band0.86 to 3.35 pounds per breast

Related Questions

Is Cup Size A Bigger Than B?

An A cup is smaller than a B cup because it only has a one-inch difference between the bust and band sizes. A B cup has a two-inch difference. On the other hand, a C cup has a three-inch difference, making it bigger than a B cup.

How Common Are B Cups?

B cups are common in America since 44% of American women have the B cup size. This size is followed by the C cups, which comprise 28% of the female population.

How to Get the Correct B Cup Bra Size Measurement?

To get the right B cup bra size, measure the underbust area to get the band length. After measuring the overbust, get the difference between the two to get your actual B cup.

Bra Size Measurement & Cup Size | A, B, C, D, DD Bra Sizes AND Extra Large Breasts


B cups are not very big as they extend only around 2 inches from your torso and weigh around 0.86 pounds each. However, these breasts are incredibly manageable and very attractive, as long as you wear the right kind of bra that fits you seamlessly.   


Allena is the Founder and Editor of The Better Fit, a platform dedicated to empowering women with practical advice on bras and fitness, inspired by her own revelation of the widespread issue of incorrect bra sizing. Her expertise and tips have been recognized by major publications such as Cosmopolitan, Better Homes & Gardens, Insider, and NBC, making her a trusted voice in women's wellness and lifestyle.