How Big Will my Breasts Grow Calculator

How Big Will My Breasts Grow Calculator

The female body has the ability to change and develop over the years. That is, from childhood to adulthood. One of the areas that change evidently over time is her breasts. 

Being able to predict how much the breast will be is not exactly accurate. It’s at best a scientific guesswork.

We have made the ‘How Big Will my Breasts Grow Calculator’ as mathematical and scientific as it can be, but we cannot guarantee that it’s predictions are accurate.

This is because there are some dynamic factors that determine the size of a breast.

What determines the size of a breast?

1. Genetics

The most significant factor when it comes to determining your breast size is genetics. Genetics plays a significant role in determining breast size. If your mother and grandmother have large breasts, it’s more likely that you will as well. 

Genetics influence the overall shape and size of your breasts by determining the amount of fatty tissue and glandular tissue present in your breasts. This tissue composition can vary significantly from person to person and can affect the size, shape, and firmness of your breasts.

2. Body Weight

Aside from genetics, body weight is another factor that can influence breast size. Breasts are composed of fatty tissue, connective tissue, and glandular tissue, and changes in body weight can affect the amount of fatty tissue present in the breasts.

If you gain weight, your breasts may become larger as they store more fatty tissue. Conversely, if you lose weight, your breasts may become smaller as your body burns fat for energy. However, the amount of weight loss required to significantly affect breast size varies from person to person. 

Your body weight will be used mainly to determine your breast size and predict your future breast in this calculator. This is based on data that will be presented later in this post. So, keep reading. 

3. Pregnancy

Another factor that greatly affects breast size is pregnancy. During pregnancy, the body undergoes a variety of hormonal changes in preparation for breastfeeding. These hormonal changes can cause the breasts to become larger and more sensitive as they prepare to produce milk.

As pregnancy progresses, the breasts may continue to increase in size and become larger. This is due to an increase in glandular tissue and an increase in the amount of fatty tissue stored in the breasts.

 4. Age

Age is definitely another factor that determines breast size.  As women age, their bodies go through a variety of changes, including changes to their breast tissue.

As women approach menopause, their hormone levels begin to shift, which can cause a decrease in glandular tissue, mammary glands, and fats. This can cause the breasts to become less firm and appear smaller in size.

Additionally, as women age, their skin loses elasticity, which can cause the breasts to sag and appear less firm. This is a natural part of the aging process and there’s nothing to be ashamed of. 

So How can we predict a Breast Size?

Having considered all the factors that influence breast size. You can see clearly that it is dependent on many factors that cannot be predicted. For example, the breast size of a girl can depend on either the genetics of the father or the mother. Being a family does not necessarily mean the genetics will follow that of the mother. 

For this calculator, we’ll be using body weight as our basis of prediction. 

 Research shows a woman’s breast usually contributes to about 3.5% of the total weight

So with this, if we figure out what the body weight is and what portion of it the breast contributes we can determine the ratio of a lady’s breast weight in comparison to the rest of the body parts. With this, we can estimate what the breast size will be if the body size increases in the future using the already established ratio of proportion.

The algorithm is more complicated than these but this is a simple way to explain it.

Who can this calculator work for?

The calculator is suitable for any woman who can identify their current weight. It, however, can work better for teenagers who are yet to attain puberty. Anyone else can use it as far as they can guess what their future weights will be. 

Although body weight is not the only factor that affects breasts, it is the most predictable and stable parameter. And even that is not enough basis because different kinds of breasts have varying density, some have more tissues than others while some have more fat than others.

Anyway, the calculator can come in handy for any woman because their breasts change at different stages of life.

How often does a woman’s breast size change?

A woman’s breasts constantly change at different points in time due to the way her system is built. Here are some common times when breast size may change:

During menstrual Periods

During a woman’s menstrual cycle, hormone levels fluctuate, which can cause temporary changes in breast size and shape. Some women may experience breast tenderness, swelling, or a feeling of fullness in the days leading up to their period. These changes are usually temporary and resolve on their own once the menstrual cycle is over.


Puberty is a time of significant hormonal changes that can cause breast development. During puberty, the ovaries begin producing estrogen, which stimulates the growth of the milk ducts in the breasts. This growth can cause the breasts to become larger and more developed. Breast development usually occurs between the ages of 8 and 13, but can continue until the age of 18 or beyond.


As mentioned earlier, pregnancy can cause significant changes in breast size and shape due to hormonal changes. But not just during that period, breastfeeding can also cause a change. 

During breastfeeding, the breasts may become larger and feel more full and heavy due to an increase in glandular tissue and milk production. This can cause some women to experience discomfort or soreness in the breasts. Additionally, the areolas (the darker area surrounding the nipples) may become larger and darker in color during breastfeeding.

After breastfeeding has ended, the breasts may gradually return to their pre-pregnancy size and shape. However, the extent of these changes can vary depending on factors such as the length of time spent breastfeeding, the frequency of breastfeeding, and the number of pregnancies a woman has had.

Other factors that can cause changes in breast size include certain medical conditions such as polycystic ovary syndrome (PCOS) or thyroid disorders. Additionally, certain medications such as birth control pills or hormone replacement therapy can cause changes in breast size and shape.

How Do I  Determine My Current Breast Size?

There are available options for you to determine your current breast size. 

First, you can measure around your breast to figure it out. 

  1. Measure your band size: You can do this by using a soft measuring tape to measure around the under part of your bust. You need to make sure the tape is snug but not too tight.
  1. Measure around your bust: This is by measuring around the fullest part of your bust. In this case, as well, you have to make sure the tape is snug but not too tight around the area. 
  1. Calculate your cup size:  To do that, simply subtract your band measurement from your bust measurement. The difference between these two measurements will give you your cup size. For example, if your band measurement is 34 inches and your bust measurement is 36 inches, the difference is 2 inches, which corresponds to a B cup. And that equates to a 34B. 

Secondly, the ‘How Big Will My Breasts Grow Calculator’ can help estimate your current breast weight using your body weight. 

Want to figure that out? Let’s get straight into it! 

How to Use the How Big My Breast Size Grow Calculator? 

The ‘How Big Will My Breasts Grow Calculator’ consists of two parts that calculate both your present breast size and your possible breast size in the future. To make use of the calculator, all you need is to know your current body weight and a future possible body weight. 

For the first part:

1. Enter your body weight in kg.

2. You can decide to go with 3.50% as the percentage of your breast weight in proportion to your body or edit it if you feel yours is different. 

At this point, your current breast weight based on your body weight will appear below. Also, you should see a range of breast sizes consisting of both letters and numbers (band size and cup size). 

Make sure to crank up or crank down the percentage slider until you see your current breast size.

Note that the breast weight and sizes are automatically calculated based on the formulas found here on Wikipedia.

How Big Will my Breasts Grow Calculator

For the second part:

  1. Enter what you think your future weight will be. 

After successfully completing this process, in the same way, your breast weight based on body weight in the future and what your future breast size should fall within will be presented below. 

The Flexibility of the ‘How Big Will My Breasts Grow Calculator’.

We earlier mentioned the data that says a woman’s breast usually contributes to about 3.5% of the total weight but some other sources suggest a different number. For example, According to a study published in the International Journal of Obesity, breast tissue makes up approximately 1-3% of a person’s total body weight, with a mean of 2.4% for women. 

This is why the calculator allows you to slide in any number between 1 and 5. 

In addition,

  1. the calculator also helps you estimate what your breast weight is at the moment.
  2. It doesn’t limit your future breast size calculation to your siblings or mother’s breast. It’s mostly objective.
  3. The calculator doesn’t discriminate with age.
  4. It doesn’t require much input. You only need to enter your weight.

You can as well easily use the calculator without any hindrance of any sort.

Frequently Asked Questions about the ‘How Big Will My Breasts Grow Calculator’

1. How are the breast weights estimated?

The breast weights are estimated based on the mathematical formulas found on this Wikipedia page.

2. Who can use the calculator?

Any woman that knows her weight.

3. How are the breast sizes estimated?

The breast sizes are estimated based on the mathematical formulas found on this Wikipedia page.

4. How accurate is the calculator?

The ‘How Big Will My Breasts Grow Calculator’ is just an estimation tool for the sake of adventure. It can help you turn your imagination. It is not a medical or health tool.

Love your boobs!

Embracing your body and your boobs is something no one can give. While we believe your breasts could grow continually and change due to the different changes that can occur in a woman’s body, accepting it and loving it no matter what at every point in time gives you the confidence you need. 


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