Biology and You

You and Your Body

How much water does the human body contain?

The average human body is between 50 and 65 percent water; a newborn baby’s body can be up to 78 percent water (by age one, it drops to about 65 percent). Adult males on the average have a higher percent of body water than adult females—around 60 percent— because males have less body fat (in fact, body fat contains 10 percent water, and bone has 22 percent water). Various organs of the body also contain various percents of water. For example, on the average, the adult human brain is about 70 percent water; the lungs are about 90 percent water; and our blood is about 83 percent water.