How Many Bones Does a Baby Have?

How many bones does a baby have? The answer might just surprise you. Read on to find out why and how it changes through their development.
A fully grown adult has 206 bones (give or take).

But what about those tiny tots whose bodies are still growing?

Surely fewer—they’re smaller, after all—right?

How many bones does a baby have?

The answer might surprise you.

So, hop on board, mama.

It’s time to explore the wonderful world of osteology (yep, that’s the study of bones).

In this article: 📝

Are there 206 or 213 bones in the human body?

Okay. Before we look at the bambinos, let’s start with your body.

As an adult human, you’ll have between 206 and 213 bones.

Why isn’t this an exact number?

Well, we’re all made a little differently.

Some people have things like extra ribs and vertebrae, so there’s quite a bit of variation in the population.

Do babies have more bones than adults?

Yes! A newborn has between 270 and 300 bones. So that’s about 100 more bones than you.

But in a baby, some of those ‘bones’ are made from a softer material called cartilage.

(We adults have some cartilage too, which allows us to fold the top of our ears over themselves.)

As your baby grows up, many of those pieces of cartilage are replaced by harder bones.

Your baby’s kneecaps, for example, are made from cartilage right now.

But, as they grow up, the soft cartilage will harden into bone.

This will happen between the ages of two and six.

Why do babies have 300 bones at birth?

As well as becoming ossified (which means turning into hard bone), some of your baby’s bones will begin to fuse as they get older.

The process will only finish when they reach adulthood.

So why does this all happen?

Well, a baby’s larger set of soft bones serves an important purpose—it’s pretty cozy in the womb, and they’ve got to be able to make themselves at home in there.

And birth? Well, we all know that’s a bit of a squeeze.

Your newborn baby’s skull, for example, is actually made up of 5 plates of bone.

This means that if you have a vaginal birth, the skull is not damaged during delivery.

Instead, the soft plates of bone squeeze together and overlap neatly, a bit like the tiles on the roof of your house.

The plates in the skull are connected by tough, fibrous tissue.

Some spots are particularly soft on a baby’s head.

These are called fontanelles and are places where the plates haven’t joined yet.

But don’t worry, the soft spots are covered by a protective membrane—gently touching them shouldn’t be a problem.

The plates (and the gaps between them) mean there’s enough room for your baby’s head to grow.

And that’s a good thing!

In the three months after birth, your baby’s brain grows rapidly.

Researchers found that during this time, a newborn’s brain grows from about a third of the size of an adult brain to just over half its size.

After that, the skull plates begin to fuse, and the fontanelles start to disappear.

Do kids have more bones than adults?

Yes, because the bone fusing process carries on for many years.

For girls, it tends to finish between the ages of 13 and 15, and for boys, between 15 and 17.

By the time they’ve reached 25 years old, your not-so-little one’s bones will have stopped growing altogether.

And here comes a plot twist.

Bones don’t just sit there—even in adults who have stopped growing.

Every ten years, your whole skeleton regenerates itself in a process known as remodeling.

This is why getting enough calcium and vitamin D is crucial for your little one (and you!), as they’re both vital for this process.

So, how many bones does a baby have?

Your newborn baby has between 270 and 300 bones—that’s a lot more than you.

But, as they grow and develop, your little peanut’s bones will fuse and harden.

By the time they’ve reached 25, they’ll have their full adult set.

That’s a lot of growing to do.

And it’s only the beginning.

Enjoy every moment, mama!