Human DNA is approximately an average of 6 feet, 6 inches in total length. There are roughly 3 billion base pairs in this length, and it is divided into 23 chromosomal pairs.
The length of human DNA and its compact home in the nucleus of cells is comparable to fitting 24 miles of thread into a single tennis ball. Each chromosome is a different length, according to the Human Genome Project. Individual chromosomes are made up of between 50 million and 300 million base pairs.
The base pairs that form human DNA are made of pairs of adenine and thymine or guanine and cytosine. These pairs create the roughly 30,000 genes contained in the human genome.