How Big Will My Boobs Be?

As an Amazon Associate we earn from qualifying purchases.

Many ladies wonder how big will their boobs be, especially if they are just starting puberty. Breasts develop at different ages and at different rates. It all depends on genetics. Each one of your breasts can have different proportions, too. We talk about how big your breasts can get in our article below.

How Big Will My Boobs Be?

In the United States, the average bra size is 34DD. In the U.K, however, it is 36DD. The size of your breasts can differ because of age, genetics and your weight.

A woman wearing a gray dri fit shirt

Breast size will also differ from one lady to another. The size of your breasts can change during your monthly period, during pregnancy, after giving birth and while breastfeeding.

What Determines the Size of My Breasts?

Listed below are the reasons why breast size is different from one women to the next.

Graphic image with a featured drawing of a woman wearing a matching blue undergarments while holding a yellow tape measure in her chest trying to determine her breast size

Factors That Determine Breast Size

FactorEffect on Breast Size
Family historyGenes influence hormone levels, which can then affect breast tissue
AgeBreasts grow during puberty
Body weightAn increase in body weight can increase body fat in the breasts
MenstruationBreasts grow as a response to increased progesterone and estrogen levels
Pregnancy and nursingProlactin promotes the growth of breast tissues called mammary alveoli

Family Background 

One thing that has the biggest contributions to the size of your breasts is your genetics. Your genes have lots to do with your characteristics, including the size of your breasts. 

However, just because your mom is a D cup does not guarantee that you’ll be one too. There are other factors that influence the size of your breasts.

Your Age

Your boobs may continue to grow or shrink depending on your age. Breasts start growing at puberty. Not all teens start developing breasts at the same time.

Breast growth depends on the amount of estrogen, a female hormone, you are producing. Your breasts can start growing at the age of 10 and typically stop growing once you are 18 to 20 years old.

As you get older, your breast tissues will begin to shrink because of tissue dehydration. Later on in life, your breasts will start to sag and get smaller.

Body Weight

Changes in your body weight can also affect the size of your breasts. Your breasts are made up mostly of fat tissues, so the more fatty tissues you have, the greater chance you’ll have bigger breasts and vice versa.

Your Period

Menstruating means having more hormones in your body. During your menstrual cycle, you may experience premenstrual syndrome (PMS) which includes pain in your lower abdomen and back, headaches, mood swings and tender swollen breasts that are painful to touch.

These symptoms are all because of the change in the amount of estrogen and progesterone in your body. These hormones can stimulate milk ducts making your breasts more tender and larger. After your period, your breasts will return to their normal size.

Pregnancy and Nursing

Pregnancy can cause massive breast size changes because of your hormones changing. These changes are the bodies way of preparing your breasts to nurse a baby.

A girl wearing a gray tank top

How to Determine Your Bra Size

Since not all breasts are created equal, it is very important to measure them to get your bra size. Having the right size of bra can keep your breasts healthy and in shape.

So here are the three parts that you should measure to know your size.

  • Measure the length around your torso with a tape measure. This measurement is called the band. 
  • Next, measure the length across your the fullest part of your breasts, which is commonly known as the bust.
  • Lastly, find the cup size of your breasts. Find the difference between the band measurement and the bust measurement. 1 inch difference equals an A cup, 2 inches equals a B cup, 3 inches equals a C cup and so on.

Related Questions

Are There Conditions Associated With Breast Size?

Breast size can be influenced by conditions such as cysts, mastitis or inflammation. People with bigger breasts may also experience more tension and pain in the back, shoulders and neck.

Is It Normal for Breasts to Have Different Sizes and Weights?

It is normal for your breasts to have different sizes and weights because of hormonal imbalances and different growth rates. Although having uneven breasts can be unsightly, you can add padding or select a bra that is designed for uneven breast sizes.

How Do You Know When Your Breasts Are Fully Grown?

Typically, breasts reach full development between the ages of 17 and 18. The areolas and nipples should darken, and the breasts should become more rounded when fully mature.

Conclusion

Breasts come in all shapes and sizes. The cup sizes range from AAA all the way to ZZZ, though the most common sizes are A, B, C, and D. Breast size is determined by your genetics, hormones, age, weight and other factors.

   

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.