Most of the time, the values for 'Size' and 'Size on disk' will be very close to matching when checking a folder or file's size, but what if there is a huge discrepancy between the two? Today's SuperUser Q&A post looks at the answer to this confusing problem.. Why there is a big difference between the size and size on disk? How to narrow the difference? This post will tell you all the answers and extra useful tips.
No matter what file system you select, Size on Disk will always be bigger than actual file size, unless the size of the file is nearly divisible by the cluster size. If you will be using that drive to store files from a Mac as well as a PC, then stay with the ExFAT format.. There's a serious size difference between the Size of this folder and the "Size on disk". See below. I expect minor difference, but this is around a 1:3 ratio, 764mb vs 2.27GB. The folder was copied from to a Flash / USB drive. On my C: drive, it's 772mb actual / 785mb on disk.