Here are your breast development stages: named after British pediatrician and professor JM Tanner. Doctors simply call it the Tanner-scale.
Developing the actual full size of your breast will start anywhere from age 8 and when you are between 17-19.
Please note that the "age" indicates an average. This age can vary depending upon ethnic groups and genetics.
Stage 1: age 8-12: Nipple elevation only. This is a wide age range but we are all different. At first the only thing that will happen is that your nipple will stand out a bit.
Stage 2: age 13: About a year or so later, your breast bud will form. This stage is called “budding”; your areola (that’s the darker area around the nipple) will get a little bit larger.
Stage 3: age 14: Another year later, your breasts will start to get more elevated and your areola will widen further.
Stage 4: age15-16: Your breast size might stay unchanged, or get fuller. Also your breasts will begin to take shape. Your nipple will stick out and might form a secondary mound.
Stage 5: age 17-19: Your breasts will get fuller and you will reach your final adult breast size.