Science, Tech, Math › Science How Many Atoms There Are in the Human Body Atoms in the Body Share Flipboard Email Print Andrew Brookes / Getty Images Science Chemistry Biochemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated April 05, 2019 Have you ever wondered how many atoms are in the human body? Here's the calculation and answer to the question. Short Answer There are approximately 7 x 1027 atoms in the average human body. This is the estimate for a 70 kg adult human male. Generally, a smaller person would contain fewer atoms; a larger person would contain more atoms. Atoms in the Body On average, 87 percent of the atoms in the body are hydrogen or oxygen. Carbon, hydrogen, nitrogen, and oxygen together account for 99 percent of the atoms in a person. There are 41 chemical elements found in most people. The exact number of atoms of the trace elements varies widely according to age, diet, and environmental factors. Some of these elements are needed for chemical processes in the body, but others (e.g., lead, uranium, radium) have no known function or are toxic contaminants. Low levels of these elements are a natural part of the environment and typically do not cause health problems. In addition to the elements listed in the table, additional trace elements may be found in some individuals. Reference: Freitas, Robert A., Jr., Nanomedicine, http://www.foresight.org/Nanomedicine/index.html, 2006. Atomic Composition of a Lean 70-kg Man Element # of Atoms hydrogen 4.22 x 10 27 oxygen 1.61 x 10 27 carbon 8.03 x 10 26 nitrogen 3.9 x 10 25 calcium 1.6 x 10 25 phosphorus 9.6 x 10 24 sulfur 2.6 x 10 24 sodium 2.5 x 10 24 potassium 2.2 x 10 24 chlorine 1.6 x 10 24 magnesium 4.7 x 10 23 silicon 3.9 x 10 23 fluorine 8.3 x 10 22 iron 4.5 x 10 22 zinc 2.1 x 10 22 rubidium 2.2 x 10 21 strontium 2.2 x 10 21 bromine 2 x 10 21 aluminum 1 x 10 21 copper 7 x 10 20 lead 3 x 10 20 cadmium 3 x 10 20 boron 2 x 10 20 manganese 1 x 10 20 nickel 1 x 10 20 lithium 1 x 10 20 barium 8 x 10 19 iodine 5 x 10 19 tin 4 x 10 19 gold 2 x 10 19 zirconium 2 x 10 19 cobalt 2 x 10 19 cesium 7 x 10 18 mercury 6 x 10 18 arsenic 6 x 10 18 chromium 6 x 10 18 molybdenum 3 x 10 18 selenium 3 x 10 18 beryllium 3 x 10 18 vanadium 8 x 10 17 uranium 2 x 10 17 radium 8 x 10 10 Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "How Many Atoms There Are in the Human Body." ThoughtCo, Aug. 26, 2020, thoughtco.com/how-many-atoms-are-in-human-body-603872. Helmenstine, Anne Marie, Ph.D. (2020, August 26). How Many Atoms There Are in the Human Body. Retrieved from https://www.thoughtco.com/how-many-atoms-are-in-human-body-603872 Helmenstine, Anne Marie, Ph.D. "How Many Atoms There Are in the Human Body." ThoughtCo. https://www.thoughtco.com/how-many-atoms-are-in-human-body-603872 (accessed April 21, 2021). copy citation How Many Atoms Are There in a Human Cell? Chemical Composition of the Human Body How Many Atoms Exist in the Universe? Elemental Composition of the Human Body by Mass What Are the Elements in the Human Body? Calculating the Number of Atoms and Molecules in a Drop of Water The Elemental Composition of the Human Body How to Balance Chemical Equations 20 Fun Oxygen Facts for Kids How Much of Your Body Is Water? How Much Are the Elements in Your Body Worth? What Happens to the Human Body in a Vacuum? What Is the Sun Made Of? Table of Element Composition How to Convert Grams to Moles and Vice Versa How Many Elements Can Be Found Naturally? How Many Carbon Atom Moles in One Mole of Sucrose?