# 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 :-) Sep 15 '19 at 4:00
• @jamesqf as in - "our blood carries oxygen through our body - how much oxygen does it carry at a given point?" Sep 15 '19 at 10:55
• Don't forget that all of the water and many of the organic compounds in our bodies also contain oxygen... Sep 15 '19 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. Sep 15 '19 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 :] Sep 16 '19 at 9:03