If the DNA (deoxyribonucleic acid) molecules in a single human cell were stretched out and laid end-to-end they would measure approximately 6.5 feet (2 meters). The average human body contains 10 to 20 billion miles (16 to 32 billion kilometers) of DNA distributed among trillions of cells. If the total DNA in all the cells from one human were unraveled, it would stretch to the sun and back more than 500 times.