dna total number of nucleotides
home 1 Length of one nucleotide pair in a DNA helix: 3.4 angstroms. 2  Average number of nucleotide pairs in a single human DNA molecule: 1.5 x 10^8. 3  Estimated total number of nucleotide pairs in a human cell: 6 x 10^9. 4  The average size of a human cell is 10 micrometers.