The 38B bra size is a fairly common size. 38B boobs can be considered medium to large sized, and with them you’ll have a wide selection of different bra styles.
In this article, we’ll look at how to measure if you’re a 38B bra size, how big this size is, what 38B breasts actually look like, what are the sister sizes of this bra size, and everything else you may want to know about it.
What Is a 38B Bra Size?
A 38B bra size is the bra size where the band measurement (measured right under the breasts) equals 38 inches and the bust measurement (measured at the center of the breasts where they’re the largest) equals 40 inches.
This may sound confusing, so let’s clear it up.
Bra sizes are comprised of a “number” component and a “letter” component (38B, 38C, 34A, and so on). To get the right bra size for you, it’s important to get both components right.
Let’s see how to do that.
The first step is to find your band size. To do that, wrap a measuring tape around your ribcage, just below your breasts. Make sure the tape is snug, but not too tight.
The tape should be parallel to the ground and should not be twisted. Take note of the measurement in inches.
Since bra sizes are even numbers, if you get an odd number, increase it to the nearest even number. For example, if you get 37 inches, increase it to 38 inches.
The number you get this way is your band measurement.
In a 38B bra size, the band size measured like this will equal 38 inches.
Next, measure your bust size. Wrap the measuring tape around the fullest part of your bust, making sure the tape is parallel to the ground and not twisted. Take note of the measurement in inches.
In a 38B bra size, the bust size measured as explained here will be equal to 40 inches.
To determine your cup size, subtract your band size measurement from your bust size measurement. The difference between the two measurements will correspond to a letter in the bra size table below.
For example, if the difference is 1 inch, your cup size is A, if it’s 2 inches, your cup size is B, and so on.
In a 38B bra size, the difference between the bust size and the band size is 2 inches (38 inches – 36 inches = 2 inches). That’s where the “B” in “38B” comes from. The “38” in “38B” comes from the band measurement.
More About the 38B Bra Size
The B cup size is very common, although the 38B bra size is not as common as other B cup sizes, such as the 34B. Still, you have a very good selection of 34B bras, both in terms of style and color.
The B cup size (including the 38B size) is along the C cup size the most desirable size. It’s not too small, but it’s also not large enough to cause back pain or similar issues.
What 38B Boobs Look Like (38B Bra Size Examples)
We discussed a lot about the 34B bra size, but we didn’t show what it looks like. So, here we’ll give some examples of celebrities that are thought to wear a 38B bra.
Although the B cup size is very common with celebrities, this is more true for the 32B and the 34B bra sizes. Still, there are prominent celebrities who wear the 38B bra size as well.
Among those, a famous example is American singer Kelly Clarkson.
38B Sister Size (38B Bra Size Equivalent)
The closest sister sizes of the 38B are the 36C and the 40A. The 36C is one cup size larger and one band size smaller, while the 40A is one cup size smaller and one band size larger. Some other sister sizes of the 36B are the 32DD and the 34D.
If you’re not familiar, sister bra sizes are different sizes that have the same cup volume. For example, the 32DD, 34D, 36C, 38B, and 40A will all hold a similar amount of breast tissue, since the band size of sister bra sizes increases as the cup size decreases.
Sister bra sizes can be useful if you can’t find a bra in your exact bra size. In such a case, a sister bra size is an option. Another use case of sister bra sizes is if your exact bra size isn’t comfortable enough even though the cups fit well.
For example, the underband might be too tight or too loose. If the cups fit well but the underband is tight, you can try a sister size up (one band size larger and one cup size smaller. For example, if the band of a 38B bra is tight, try a 40A.
On the other hand, if the cups fit but the underband is loose, you can try a sister size down (one band size smaller and one cup size larger). For example, if the band of a 38B bra is loose, try a 36C.
38B Bra Size in Cm (38B Bra Size in Europe)
Measured in centimeters, a 38B bra size means that your band measurement equals ~97 cm and your bust measurement equals ~102 cm. The difference between the bust size and the band size is roughly 5 cm, which translates to a B cup size.
38B Bra Size in Inches
Measured in inches, a 38B bra size means that your band measurement equals 38 inches (that’s where the “38” in “38B” comes from) and your bust measurement equals 40 inches. The difference between the bust size and the band size is 2 inches, which translates to a B cup size (that’s where the “B” in “38B” comes from).
38B vs 38C
A 38B bra size and a 38C bra size both have the same band measurement of 38 inches (which is where the “38” in 38B and 38C comes from). But, a 38B bra size has a bust measurement of 40 inches, while a 38C bra size has a bust measurement of 41 inches.
Given this, a 38B bra size is one cup size smaller than a 38C bra size. In other words, 38B boobs are one inch smaller in measurement than 38C boobs.
38B vs 36C
A 38B bra size and a 36C bra are sister sizes. More specifically, the 36C bra is one sister size down from a 38B. This is because a 36C bra is one band size smaller, but one cup size larger from a 38B bra size.
36B vs 38B
A 38B bra size and a 36B bra size both have a 2-inch difference between the bust size and the band size. But, a 38B bra size has a band measurement that’s roughly 2 inches larger compared to the 36B (40 inches compared to 38 inches). Also, a 38B bra size has a bust measurement that’s 2 inches larger compared to the 36B bra size (40 inches compared to 38 inches).
38B Bra Size Infographic
What Bust Size Is a 38B?
A woman wearing 38B will have a bust size of 40 inches (~102 cm). Her band size will be 38 inches, which means that the difference between the bust size and the band size will equal roughly 2 inches (that’s why the cup size equals B).
What Is the Next Bra Size From 38B?
If you go one band size larger, the next bra size from 38B is 40B. If you go one band size smaller, the next bra size is 36B. On the other hand, if you’re referring to cup sizes, the next bra size from 38B is 38C (one cup size larger) or 38A (one cup size smaller).
Is 38B Bigger Than 36C?
38B bra size has a larger band size than a 36C (38 inches compared to 36 inches). But, a 36C has the larger difference between the bust and the band size compared to the 38B (3 inches compared to 2 inches). Given this, the 38B and the 36C are sister sizes, meaning that they’ll hold roughly the same amount of breast tissue.
In this article, you learned all you need to know about a medium to large bra size – the 38B bra size. Among other things, you learned how big 38B breasts actually are, how to measure if you should be wearing a 38B bra, what are the sister sizes of this bra, and what 38B boobs actually look like.
The founder, editor, and writer of most articles on Ultimate Bra Guide. An experienced bra fitting specialist turned blogger. My website Ultimate Bra Guide has been featured in relevant publications such as Glamour, Bustle, Elite Daily, Alldaychic, Everyday Feminism, and so on. Get to know me better at our about page.