Home » Articles » How Big Is a 38C Bra Cup Size?

How Big Is a 38C Bra Cup Size?

As an Amazon Associate we earn from qualifying purchases.

When it comes to bra sizes, many women find it challenging to determine their correct size. The bra sizes are confusing because it is not simply about the numbers but also about knowing what they mean. For example, some tend to wonder how big a 38C bra size is.

How Big Is 38C Bra Size?

If your bra size is 38C, your band is around 34 to 35 inches, and your bust measurements are 40 to 41 inches. For a C cup size, the bust measurement is three inches more than the band measurements. The sister sizes of a 38C are 36D and 40B.

A woman wearing a black bra

When you determine your size, the main thing to realize is that there is a measurement number for every cup size. So, if your measurement falls between two cup sizes, you should round down to the smaller or up a bigger size. That’s where sister sizes come in handy.

Which is Larger, 38C or 38B?

A 38B, for example, will have a less wide underwire and shallower projection level than a 36C. This typically means the underwire on a 38C is wider, and the level of projection is deeper. That is why it is important to know your bra size.

However, there are a few things to bear in mind.

  • Each lingerie brand has its sizing scale. A 38C measurement from one brand might be smaller than a 38C measurement from another.
  • Cup sizes are RELATIVE to band sizes. For example, the C cups on smaller band sizes such as 30 are way smaller than the B cups on larger band sizes such as 42. This is known as sister sizing.

Therefore, cup size is a measure of volume, not breast size.

How Do 38C Breasts Appear?

The appearance of breasts in every woman is usually determined by a variety of factors, including:

  • Lifestyle
  • Body shape
  • Genetics
  • Rapid weight loss or weight gain

38C breasts are less perky and denser and are likely to start sagging early. Different factors like rapid weight gain or weight loss can also cause sagging of your 38C breast. Additionally, age can affect the elasticity of the skin resulting in sagging.

Like 38D cup sizes, 38C boobs also fall on the bigger side of average, many women with size will opt for surgery to get them smaller. Always remember that breast implants and surgery are never the solutions to insecurities and self-esteem problems.

A woman sitting on a bed wearing a black bra

How Do You Know if You’re Wearing the Right Size Bra?

If your breasts spill out of your cups, or if they create a uni-boob effect, it’s time to go up in cup size. An excellent way to test this is by putting two fingers underneath each breast and lifting them to fill the space in the cups.

If there’s still too much room, try going up one more cup size. If your straps dig into your shoulders, or you find yourself adjusting them throughout the day, it may be time for a different bra style, such as an unlined demi-cup or strapless.


It is important to note that no one size will fit all, and different styles work for other people. In addition, several factors can cause your breasts to wear the incorrect bra size, such as diet, pregnancy, aging, and so on. The best thing you can do is find one that works for you and your body type.

Hi there, I’m Allena, Founder and Editor of The Better Fit. I’ve always had a passion for finding ways to help women improve various areas of their lives. I have researched and worked to create this website so women would have a place to come and be informed about an article of clothing they literally wear every day.