# How much Oxygen can the Human body carry?

Basically - the title: How much Oxygen does a human body carry at a single point?

What have I tried: A friend of mine has done some calculations and came up with the following numbers. Neither of us are biologists or have higher degrees in biology. His calculation went something like:

• Our body absorbs about 0.033g of Oxygen when we inhale (source).
• That's about 0.00103 moles of oxygen.
• Through ATP reaction that's about 0.00515 moles of ATP
• We have 270 millions of hemoglobin per red blood cell, and roughly 25 trillions of blood cells in our body (wiki), and each Hemoglobin molecule "carries" up to 4 oxygen molecules.
• Thus, in total, our body's hemoglobin can carry about (2.5 * 10^13) * (270 * 10^6) * 4 = 1.437 grams of oxygen

How far is the 1.437g number have?

Related (but not the same question) question I found here: How much energy we get from oxygen?.

Note: this is specifically about oxygen we use in our respiratory system - and not the oxygen in the water :]

• What do you mean by "carry"? My first thought is a strong person carrying a large Dewar vessel full of liquid oxygen :-) – jamesqf Sep 15 at 4:00
• @jamesqf as in - "our blood carries oxygen through our body - how much oxygen does it carry at a given point?" – Benjamin Gruenbaum Sep 15 at 10:55
• Don't forget that all of the water and many of the organic compounds in our bodies also contain oxygen... – theforestecologist Sep 15 at 19:28
• Presumably you have your own reasons for asking this question, but you should not be surprised if nobody else is interested unless you explain why it is of interest. – David Sep 15 at 19:59
• @David I am interested in this because it is interesting and because we are trying to practice doing these calculations as non-biologists :] – Benjamin Gruenbaum Sep 16 at 9:03