I was looking at this chart of the Composition of the human body.
Let’s assume an average adult human weighs about 150 pounds.
The human body is about 70-75% water so
75% of 150 pounds = 112.5 pounds of water
1 gallon of water weighs about 8 pounds
112.5 pounds of water in the average human ÷ 8 pounds per gallon = 14.0625 gallons of water in the average person.
So if we used the “percent of mass” column in the above link to arrange the chemical composition of a human being on a table, is this what would we have?
14 gallons of water
27 pounds of carbon
3 pounds of nitrogen
2 pounds of calcium
1.6 pounds of phosphorus
6 ounces of potassium
6 ounces of sulfur
3 1/2 ounce of sodium
3 1/2 ounces of chlorine
1 ounce of magnesium
and about 3 1/2 ounces of about 50 trace elements