It's difficult to predict exactly how big your breasts will get, as there are many factors that can affect breast size and shape, including genetics, body weight, hormonal changes, and pregnancy.
Breast size is largely determined by genetics, and some women may naturally have larger or smaller breasts than others. Body weight can also play a role, as breast tissue is composed of fat cells and may increase or decrease in size as body weight fluctuates.
Hormonal changes, such as those that occur during puberty, pregnancy, or menopause, can also affect breast size and shape. During these periods, the body may produce more estrogen, which can cause the breast tissue to grow and change.
Breast size can also be affected by external factors, such as the use of hormonal birth control, certain medications, or a medical condition such as polycystic ovary syndrome (PCOS).