---
title: "Femur — what it does and the numbers"
description: "The longest and strongest bone — about a quarter of adult height. What it does, where it is, the figures people look up, and the widely repeated claims that turn out"
url: https://atoneplace.net/body/femur/
site: "At One Place"
---

# Femur

**Femur: The longest and strongest bone — about a quarter of adult height.**

Bears the load of the upper body during standing and walking, and anchors the largest muscles in the body.

## Where it is

Thigh, from hip to knee.

## The numbers

- **Length:** about 26% of standing height
- **Compressive strength:** roughly 1,700–2,000 kg

## Worth knowing

Because femur length is a fairly consistent fraction of height, forensic anthropologists estimate stature from it. It is strong enough in compression to bear well over a tonne, though far weaker in bending — which is why femoral fractures come from side impacts rather than from loading.

> 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 femur do?

Bears the load of the upper body during standing and walking, and anchors the largest muscles in the body..

### Femur — key numbers

Length: about 26% of standing height. Compressive strength: roughly 1,700–2,000 kg.

## Related pages

- [Bones](https://atoneplace.net/body/bones/)
- [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/)