This is off topic now, but it seems like there is a lot of confusion about size disparity…
So, HDD (and DVDs, but not CDs) and who knows what else, are advertised with the lausy convention of using SI prefixes, which 3 decimal orders of magnitude (10^3 = 1000) apart from each other. With computers though, sizes are usually displayed with the convention that prefixes should be 10 binary orders of magnitude (2^10 = 1024) apart… This is pretty insignificant when talking about bytes and kilobytes, but when we get ot GB, things change, and it is really the suck with TB.
Your 1TB drive really has ~10^12 bytes, which, after being devided by 2^40 is only 0.9095TiB, or when divided by 2^30 – 931GiB.
Really, the easiest thing to do was just use google and type
625 * 10^9 bytes to GB
… obviously, the article has a typo.