Ask A Scientist

How many bones are in the human body? 

Asked by: Mitchell Shaw
School: St. James School, Johnson City
Grade: 4
Teacher: Mrs. O'Reilly
Hobbies/Interests: I like to play guitar.
Career Interest: Teacher

Answer from Elizabeth A. DiGangi

Assistant Professor, Binghamton University

Research area: Bioarchaeology and forensic anthropology in Latin America
Interests/hobbies: Collecting orchids, flower and vegetable gardening, hiking, Bikram (hot) yoga and spoiling my dogs rotten.

What a great question! You might think that a question such as this would have a simple answer. However, humans actually vary in the number of bones we have depending upon how old we are, believe it or not! This is due to the way our bones grow. Most bones, such as your arm and leg bones grow together from three or four separate parts. As a result, a baby has more bones than you do (almost too many to count, but hundreds) and you have more bones than your mom or dad! At your age, the different parts of your bones are still fusing or growing together. Believe it or not, you were not born with all of the bones you have right now. For example, you have only had the bones in your wrists for about three years. Those bones did not form until you were six.

By the time you graduate from high school, almost all of the different parts of your individual bones will be fused together, which will be a sign that your bone growth is complete. By the time you graduate from college (a very long time from now) you will have about 206 bones in your body. This number can be different from one person to the next. This is because many of us have round bones the size of small pebbles in some of our fingers and our toes, which aids in making them stronger. Not everyone has the same number of these special bones. Also, some adults may have some bones that are fused together that are not supposed to be fused together. This happens frequently to our spine bones when we are older (your grandma or grandpa’s age) because over the years, our spines have to handle a lot of weight and body movement every day. After a lot of time, the bones may start to break down and so they fuse together. In addition to that, some people are born with unusual bones – such as one extra rib or one extra spine bone, called a vertebra.  So this may be a longer answer to your question than you may have expected. The summary answer is humans have a different number of bones in our bodies depending on what stage of life we are in. Thanks so much for your question!

Last Updated: 3/1/17