And this is why base-ten and base-two file and memory sizes are roughly equivalent (which is somewhat useful but also causes a lot of confusion):

    2^10 bytes = 1 kiB ≈ 1 kB = 10^3 bytes
    2^20 bytes = 1 MiB ≈ 1 MB = 10^6 bytes
    2^30 bytes = 1 GiB ≈ 1 GB = 10^9 bytes
    2^40 bytes = 1 TiB ≈ 1 TB = 10^12 bytes

and so on. The relative error does grow as you move to larger and larger powers, though.