---
title: "Bones — what it does and the numbers"
description: "206 in the adult skeleton, down from about 270 at birth. What it does, where it is, the figures people look up, and the widely repeated claims that turn out to be wr"
url: https://atoneplace.net/body/bones/
site: "At One Place"
---

# Bones

**Bones: 206 in the adult skeleton, down from about 270 at birth.**

Support the body, protect the organs, anchor muscles, store calcium and phosphate, and produce blood cells in the marrow. Bone is living tissue, continuously remodelled — the skeleton is substantially replaced over roughly a decade.

## The numbers

- **Adult count:** 206
- **At birth:** about 270
- **In the hands and feet:** 106 — more than half
- **Share of body mass:** ~15%

## Worth knowing

The count falls with age because separate bones fuse: the skull plates, the sacrum and the coccyx all begin as multiple pieces. More than half of all bones are in the hands and feet — 27 per hand and 26 per foot. The femur is the longest and strongest, and the stapes in the middle ear is the smallest at about 3 mm.

## A common claim that is wrong

The count of 206 is a convention, not a constant. A minority of people have extra sesamoid bones or an additional rib, and the figure depends on whether such variants are counted.

> Structural reference only — this is not medical advice, and individual variation in every figure here is substantial. Anything concerning your own health belongs with a clinician rather than a reference page.

## Common questions

### What does the bones do?

Support the body, protect the organs, anchor muscles, store calcium and phosphate, and produce blood cells in the marrow.

### Bones — key numbers

Adult count: 206. At birth: about 270. In the hands and feet: 106 — more than half. Share of body mass: ~15%.

### Is it true that…

The count of 206 is a convention, not a constant. A minority of people have extra sesamoid bones or an additional rib, and the figure depends on whether such variants are counted.

## Related pages

- [Femur](https://atoneplace.net/body/femur/)
- [Heart](https://atoneplace.net/body/heart/)
- [Brain](https://atoneplace.net/body/brain/)
- [Blood types](https://atoneplace.net/body/blood-types/)
- [Teeth](https://atoneplace.net/body/teeth/)
- [Blood](https://atoneplace.net/body/blood/)
- [Liver](https://atoneplace.net/body/liver/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)