Hello again, all good? Yes, you could try that, i.e., subtract start from end (End - Start = Xbp), but be careful about CN segments that may already be overlapping.

For the genome size, I would obtain an official figure from the Genome Reference Consortium:

• https://www.ncbi.nlm.nih.gov/grc/human/data

This will always be an estimate, because we have not, as yet, sequenced certain parts of the genome, Also, the true length of each genome will slightly differ between individuals, and even differ between cells within the same individual due to copy number alterations and other events.

Kevin