--- title: "How many bacteria are there on Earth? about 5 nonillion" description: "about 5 nonillion How the figure is estimated, how confident it is, and what makes the scale graspable." url: https://atoneplace.net/how-many/bacteria-on-earth/ site: "At One Place" --- # How many bacteria are there on Earth? **How many bacteria are there on Earth?: about 5 nonillion** There are about ten million bacteria on Earth for every star in the observable universe. Their combined carbon is comparable to that of all the world's plants. The standard estimate is 4 to 6 × 10^30 prokaryotic cells — bacteria and archaea together — which makes them by an enormous margin the most numerous organisms on the planet. Most of them are not where you would guess: the majority live in the deep subsurface, in rock and sediment kilometres below the sea floor and the land surface, where they metabolise so slowly that individual cells may divide once a century. Ocean surface water and soil are relatively minor contributors. The figure has held up for a quarter of a century, though deep-subsurface revisions have pushed the low end down somewhat. ## How the figure is arrived at Habitat by habitat: measure cells per millilitre of seawater or per gram of soil using direct microscopic counts with a fluorescent DNA stain, multiply by the volume or mass of that habitat, and add. The deep subsurface dominates and is also the hardest to sample, so nearly all the uncertainty in the total comes from drilling cores. ## How confident it is - **Low estimate:** 4,000,000,000,000,000,000,000,000,000,000 - **High estimate:** 6,000,000,000,000,000,000,000,000,000,000 - **Spread:** 1.5× between the bounds ## Other living things and the natural world counts - [How many people are there in the world?](https://atoneplace.net/how-many/people-alive-right-now/) — about 8.2 billion - [How many grains of sand are there on Earth?](https://atoneplace.net/how-many/grains-of-sand-on-earth/) — roughly 7.5 quintillion on the world's beaches - [How many ants are there in the world?](https://atoneplace.net/how-many/ants-on-earth/) — about 20 quadrillion - [How many trees are there in the world?](https://atoneplace.net/how-many/trees-on-earth/) — about 3 trillion - [How many insects are there?](https://atoneplace.net/how-many/insects-on-earth/) — about 10 quintillion - [How many species are there?](https://atoneplace.net/how-many/species-on-earth/) — about 8.7 million - [How many people have ever lived?](https://atoneplace.net/how-many/people-who-have-ever-lived/) — about 117 billion - [How many drops of water are there in the ocean?](https://atoneplace.net/how-many/drops-of-water-in-the-ocean/) — about 27 septillion - [How many fish are there in the sea?](https://atoneplace.net/how-many/fish-in-the-sea/) — somewhere between 3 trillion and 100 trillion — nobody knows - [How many species are endangered?](https://atoneplace.net/how-many/endangered-species/) — more than 45,000 assessed as threatened - [How many bees are there in the world?](https://atoneplace.net/how-many/bees-in-the-world/) — roughly 2 trillion managed honey bees - [How many birds are there in the world?](https://atoneplace.net/how-many/birds-in-the-world/) — about 50 billion wild birds - [How many earthquakes are there each year?](https://atoneplace.net/how-many/earthquakes-a-year/) — about 20,000 located a year — around 55 a day - [How many chickens are there in the world?](https://atoneplace.net/how-many/chickens-in-the-world/) — about 26 billion alive at any moment ## Common questions ### How many bacteria are there on Earth? about 5 nonillion ### How is that estimated? Habitat by habitat: measure cells per millilitre of seawater or per gram of soil using direct microscopic counts with a fluorescent DNA stain, multiply by the volume or mass of that habitat, and add. The deep subsurface dominates and is also the hardest to sample, so nearly all the uncertainty in the total comes from drilling cores. ## Related pages - [How many people are there in the world?](https://atoneplace.net/how-many/people-alive-right-now/) - [How many grains of sand are there on Earth?](https://atoneplace.net/how-many/grains-of-sand-on-earth/) - [How many ants are there in the world?](https://atoneplace.net/how-many/ants-on-earth/) - [How many trees are there in the world?](https://atoneplace.net/how-many/trees-on-earth/) - [How many insects are there?](https://atoneplace.net/how-many/insects-on-earth/) - [How many species are there?](https://atoneplace.net/how-many/species-on-earth/) - [How many people have ever lived?](https://atoneplace.net/how-many/people-who-have-ever-lived/) - [How many drops of water are there in the ocean?](https://atoneplace.net/how-many/drops-of-water-in-the-ocean/) - [How many stars are there in the universe?](https://atoneplace.net/how-many/stars-in-the-universe/) - [How many countries are there in the world?](https://atoneplace.net/how-many/countries/) - [How many bones are in the human body?](https://atoneplace.net/how-many/bones-in-the-human-body/) - [How many stars are there in the Milky Way?](https://atoneplace.net/how-many/stars-in-the-milky-way/) - [How many atoms are there in the universe?](https://atoneplace.net/how-many/atoms-in-the-universe/) - [How many galaxies are there?](https://atoneplace.net/how-many/galaxies-in-the-universe/) ## Sources - Typical range compiled from manufacturer specifications — At One Place (/about/)