Have you ever wondered exactly how many atoms you’re made up of? Or maybe specifically how many hydrogen atoms and how many oxygen atoms are there in your body?

Well, the folks over at foresight.org have done the maths and according to them, an average 70-kg male human body contains almost 7 × 10^{27} atoms. Yes, that’s a whole lot of atoms!

Although 41 different chemical elements are commonly found in the human body’s construction, Carbon, Hydrogen, Oxygen and Nitrogen comprise 99% of its atoms. 87% of human body atoms are either Hydrogen or Oxygen. According to the estimates, 4.22 x 10^{27} of the atoms are Hydrogen atoms while 1.61 x 10^{27} are Oxygen.

Here’s the complete list of 41 elements and their respective presence:

Element |
Sym |
# of Atoms |
Element |
Sym |
# of Atoms |
Element |
Sym |
# of Atoms |

Hydrogen | H | 4.22 x 10^{27} |
Rubidium | Rb | 2.2 x 10^{21} |
Zirconium | Zr | 2 x 10^{19} |

Oxygen | O | 1.61 x 10^{27} |
Strontium | Sr | 2.2 x 10^{21} |
Cobalt | Co | 2 x 10^{19} |

Carbon | C | 8.03 x 10^{26} |
Bromine | Br | 2 x 10^{21} |
Cesium | Cs | 7 x 10^{18} |

Nitrogen | N | 3.9 x 10^{25} |
Aluminum | Al | 1 x 10^{21} |
Mercury | Hg | 6 x 10^{18} |

Calcium | Ca | 1.6 x 10^{25} |
Copper | Cu | 7 x 10^{20} |
Arsenic | As | 6 x 10^{18} |

Phosphorus | P | 9.6 x 10^{24} |
Lead | Pb | 3 x 10^{20} |
Chromium | Cr | 6 x 10^{18} |

Sulfur | S | 2.6 x 10^{24} |
Cadmium | Cd | 3 x 10^{20} |
Molybdenum | Mo | 3 x 10^{18} |

Sodium | Na | 2.5 x 10^{24} |
Boron | B | 2 x 10^{20} |
Selenium | Se | 3 x 10^{18} |

Potassium | K | 2.2 x 10^{24} |
Manganese | Mn | 1 x 10^{20} |
Beryllium | Be | 3 x 10^{18} |

Chlorine | Cl | 1.6 x 10^{24} |
Nickel | Ni | 1 x 10^{20} |
Vanadium | V | 8 x 10^{17} |

Magnesium | Mg | 4.7 x 10^{23} |
Lithium | Li | 1 x 10^{20} |
Uranium | U | 2 x 10^{17} |

Silicon | Si | 3.9 x 10^{23} |
Barium | Ba | 8 x 10^{19} |
Radium | Ra | 8 x 10^{10} |

Fluorine | F | 8.3 x 10^{22} |
Iodine | I | 5 x 10^{19} |
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Iron | Fe | 4.5 x 10^{22} |
Tin | Sn | 4 x 10^{19} |
|||

Zinc | Zn | 2.1 x 10^{22} |
Gold | Au | 2 x 10^{19} |
TOTAL |
6.71 x 10^{27} |

Since atoms make up all ordinary matter, and mass is basically a measurement of the quantity of matter, you can use this data to estimate the number of atoms in any person if you know his/her mass. (Yes, it’s always going to be an estimate.) So, if typically 70 kg worth of human is made up of 7 × 10^{27} atoms, that means every 1 kg of human is made up of 10^{26} atoms. So, if you have a guy that weighs 85 kg, he would be made up of approximately 8.5 × 10^{27} atoms (85 × 10^{26}).