when I do a full backup in cpanel, the zip file contains 453 MB. Yet in Cpanel, under Disk Space Usage, it says 627.31 Megabytes. Ive tried downloading the back up many times, and it only gives me 453 MB each time. What is happening here?
when you do a cpanel backup, all the files are been compressed and therefore there is a difference of your file size.
cpanel disk space usage seems to lag a bit behind actual disk space usage. Check back in a few hours and the figure will have updated.
That's common. Ask your host (if you have one) to update it or go into "disk space usage" and view it there.