Are my deleted contents on EasyStore really deleted?

I purchase an EasyStore External drive 8TB, but have to return to the store due to wrong information provided by the store. I did a back up of my Mac computer to the Easy store which took up approx 140 GB. Completely deleted that back-up, so the remaining capacity should show 8TB, as it did before that back-up.
However when I click on “Get Info” of the easy store icon, it shows only 7.86 TB capacity.
I want to be sure that my backup has been deleted for sure. why does it still show 7.86 TB, as if the files are still there?
Thanks for your info.

An advertised hard drive of 8TB will only show a capacity of 7.276TB on a PC because advertised capacity is Base 10 math and computers use Base 2

http://www.endmemo.com/data/diskcapacity.php

Now, in saying that … deleting files, formatting hard drives never truly deletes the data, it just changes the address table of where the data is/was.

Personally, as a test many years ago i did a full format of a hard drive with data on it to see if afterwards i could use data recovery to get my files back after the hard drive was deleted/formatted … managed to recover 99% of my data :slight_smile:

Only way to 100% delete data and make it un-recoverable, is by physically destroying the hard drive into a million pieces.