---
title: "Cells in the body — what it does and the numbers"
description: "About 36 trillion, of which roughly 80% are red blood cells. What it does, where it is, the figures people look up, and the widely repeated claims that turn out to b"
url: https://atoneplace.net/body/cells/
site: "At One Place"
---

# Cells in the body

**Cells in the body: About 36 trillion, of which roughly 80% are red blood cells.**

Cells are the structural and functional units of the body, differentiated into around 200 distinct types.

## The numbers

- **Total cells:** about 36 trillion
- **Red blood cells:** about 80% of the count
- **Bacterial cells carried:** about 38 trillion
- **Distinct cell types:** roughly 200

## Worth knowing

Red blood cells dominate the count while contributing little mass, because they are small and numerous. By mass, muscle and fat cells dominate. A 2016 estimate put human and bacterial cell counts at roughly parity — about 30 trillion each — with the bacteria concentrated almost entirely in the colon.

## A common claim that is wrong

The claim that bacteria outnumber human cells ten to one is obsolete. It traced to a 1972 estimate never intended as precise; careful counting puts the ratio close to 1:1.

> 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 cells in the body do?

Cells are the structural and functional units of the body, differentiated into around 200 distinct types..

### Cells in the body — key numbers

Total cells: about 36 trillion. Red blood cells: about 80% of the count. Bacterial cells carried: about 38 trillion. Distinct cell types: roughly 200.

### Is it true that…

The claim that bacteria outnumber human cells ten to one is obsolete. It traced to a 1972 estimate never intended as precise; careful counting puts the ratio close to 1:1.

## Related pages

- [Body water](https://atoneplace.net/body/body-water/)
- [Heart](https://atoneplace.net/body/heart/)
- [Brain](https://atoneplace.net/body/brain/)
- [Bones](https://atoneplace.net/body/bones/)
- [Blood types](https://atoneplace.net/body/blood-types/)
- [Teeth](https://atoneplace.net/body/teeth/)
- [Blood](https://atoneplace.net/body/blood/)

## Sources

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