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 × 1027 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 1027 of the atoms are Hydrogen atoms while 1.61 x 1027 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 1027 Rubidium Rb 2.2 x 1021 Zirconium Zr 2 x 1019 Oxygen O 1.61 x 1027 Strontium Sr 2.2 x 1021 Cobalt Co 2 x 1019 Carbon C 8.03 x 1026 Bromine Br 2 x 1021 Cesium Cs 7 x 1018 Nitrogen N 3.9 x 1025 Aluminum Al 1 x 1021 Mercury Hg 6 x 1018 Calcium Ca 1.6 x 1025 Copper Cu 7 x 1020 Arsenic As 6 x 1018 Phosphorus P 9.6 x 1024 Lead Pb 3 x 1020 Chromium Cr 6 x 1018 Sulfur S 2.6 x 1024 Cadmium Cd 3 x 1020 Molybdenum Mo 3 x 1018 Sodium Na 2.5 x 1024 Boron B 2 x 1020 Selenium Se 3 x 1018 Potassium K 2.2 x 1024 Manganese Mn 1 x 1020 Beryllium Be 3 x 1018 Chlorine Cl 1.6 x 1024 Nickel Ni 1 x 1020 Vanadium V 8 x 1017 Magnesium Mg 4.7 x 1023 Lithium Li 1 x 1020 Uranium U 2 x 1017 Silicon Si 3.9 x 1023 Barium Ba 8 x 1019 Radium Ra 8 x 1010 Fluorine F 8.3 x 1022 Iodine I 5 x 1019 Iron Fe 4.5 x 1022 Tin Sn 4 x 1019 Zinc Zn 2.1 x 1022 Gold Au 2 x 1019 TOTAL 6.71 x 1027

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 × 1027 atoms, that means every 1 kg of human is made up of 1026 atoms. So, if you have a guy that weighs 85 kg, he would be made up of approximately 8.5 × 1027 atoms (85 × 1026).