How Many Bones Does a Baby Have: 300 Bones at Birth

Babies are frequently described as tiny humans, but there are a few differences between a baby’s anatomy and an adult’s. After all, they have a lot of growing to do. Although babies are smaller versions of an adult in many ways, there is at least one key difference: the number of bones babies have.

When a baby is born, they actually have more bones than adults. They also tend to have more bones that are soft and flexible since they need to be more flexible. When learning to roll over, crawl, and walk, babies will eventually end up doing a lot of tumbling.

As parents, it’s important for us to have an understanding of our little ones' needs, from pregnancy to the time they’re grown. Even though knowing the number of bones that our babies have may not be helpful in a practical sense, it does help us learn and discover how our baby is growing and functioning in some ways. It’s also a pretty cool fact to bring up in a conversation with other parents.

How Many Bones Is My Baby Born With?

When babies are born, they have around 300 bones. As they age, your little one’s bones will grow and start to fuse together, which is why adults have fewer bones. These early bones are tiny, but there are a lot of them.

Babies also have more flexible bones. Instead of breaking under pressure, they have a little bit of give, so they can bend. Some of their bones are made of cartilage too, which is the same material that gives your nose and ears shape.

Cartilage is very soft and much more flexible than bone. Some of your little one’s bones are made entirely of cartilage, while others are only partially cartilage. As your baby gets older, the cartilage is slowly replaced by bone.

As babies grow, they’ll start walking and learning how to do other things, and there will probably be times when they take a tumble. Having more flexible bones is good because your little one will be learning how to do things, while adults are less likely to lose balance and fall.

Children’s bones can also reshape themselves if necessary since their bones are still growing. If they have a broken bone and it’s a little crooked, it’s possible for the bone to straighten itself out over time.

It also makes it easier for their bones to heal after an accident. These situations aren’t ideal, but it can be reassuring to know.

How Many Bones Do Adults Have?

Adults have 206 bones. Their bones are fully fused together, and some of the cartilage in their bones is gone, except for areas like the nose and ears. Bones stop growing by the time an adult hits their late teens or early 20s.

An adult’s bones are usually more brittle and hard, so instead of bending, they’ll usually just break. They don’t have the flexibility that children’s bones do. It can also take a little longer for adult bones to heal since they don’t grow in the same way that children’s bones do.

What Are Bones Made Of?

One similarity between adult and baby bones is that they are made up of the same components. Each part of the bone has its own purpose, and it helps keep our bodies structured.

1. Bone Marrow

There are four layers to any bone. The inner layer is made up of bone marrow, which is a thick, gel-like substance. It produces the blood cells that our bodies use to carry oxygen and protect us from diseases.

2. Cancellous Bone

The next layer, which protects the bone marrow, is called cancellous bone. There are actually multiple layers of cancellous bones, and it resembles a sponge. Although it’s not as hard as the next layer, it is firm and strong.

3. Compact Bone

Around the cancellous bones is the compact bone. This is the part of the bone that most people are familiar with because it’s the part we can see on skeletons in museums or science labs. It’s smooth and hard and protects the inner layers.

4. Periosteum

The final layer of the bone helps connect it with the surrounding body. It’s known as the periosteum, and it helps to nourish the bone. The periosteum is a membrane that is thin and dense, and it contains blood vessels and nerves.

Each layer is vital to the health of the bone and our bodies, so it’s important to work to keep them healthy and strong. 

What Else Should I Know About Bone Structure?

Most bones also have an area that is called a physis, or growth plate. This region is at the end of the bone, and it helps control the bone's growth. If this part of the bone breaks, it can affect how the bone grows and can even lead to some kind of deformity in the bone.

How Can I Help My Little One Develop Strong Bones?

Babies need vitamins and nutrients to help them grow. Even though bones are naturally supposed to be strong, your little one will need a bone-healthy diet to help them remain strong.

Things like protein, vitamin D, and calcium are all critical for healthy bones. Calcium is known for its bone-strengthening abilities. It helps replace cartilage with bone as your baby grows. Although you can’t really give a baby these before they’re ready for solid food, there are some ways that you can help your baby get the benefits of them.

Before Birth

Before your baby is born, they eat what you eat. That’s why a diet full of protein and calcium, among other necessary nutrients, is important for pregnant mothers. There are plenty of foods you can eat that can help the health of both you and your little one.

You can eat:

  • Pregnancy-safe dairy products, like milk or hard cheeses, which contain calcium
  • Vegetables, including broccoli and kale
  • Meats like chicken, pork, and beef
  • Tofu with added calcium

Vitamin D is also an essential part of bone health. The best way to get vitamin D is to take a supplement. Most prenatal vitamins actually have a good amount of vitamin D, but you will also need it from other sources, like drinks with it added or a vitamin D supplement.

Providing your baby with nutrients to strengthen their bones while they are still in the womb. They’re still forming their bones, so they need all the help they can get. 

After Birth

Once your baby is born, they will still need some help with a bone-healthy diet. If you’re planning on feeding with formula, you can find plenty of good baby formula with vitamin D and other nutrients for your little one.

If you’re planning on breastfeeding or bottle feeding with breastmilk, there’s an extra step. Your little one will still be getting all their nutrients from you, at least until they’re old enough to start eating baby food. 

Most pediatricians and obstetricians will recommend that breastfeeding mothers continue to take their prenatal vitamins. They might also need to take some vitamin D supplements to help bolster the amount that is in the breast milk.

Once your little one is old enough for baby foods, you can start to give them things with the necessary proteins and calcium. However, your little one should not be given cow’s milk until they are over a year old.

Your Baby’s Skeleton

Although we can’t see them, healthy bones are vital to your little one’s health. After all, without them, we wouldn’t have many of the abilities that we have. Babies have over 300 bones, so they’ll need a lot of vitamins and nutrients to help those bones grow and become stronger. 

While your baby grows, their bones will start to fuse together, eventually decreasing to roughly 206 once they are an adult.

Babies and children grow. They heal faster, and their bones are built to be durable. They are an important part of the body’s function and not only because they provide structure. They create more blood cells, which aid the immune system and help to transport oxygen.

With a baby on the way, there are a lot of things that parents need to do. Learning about the number of bones your baby has may not seem like a huge deal, but even small facts can help remind us of essential parts of our baby’s needs. 

If you’re looking for more information about your baby’s health and well-being or about pregnancy, you can check out our pregnancy and postpartum blog.


How Kids’ Bones Differ From Adults’ | Children's Healthcare of Atlanta

Strong Bones for You and Your Baby |

Your Bones (for Kids) | Nemours KidsHealth

Eating well in pregnancy | Ready Steady Baby! | NHS Inform