Why large size calculation difference: Mac Finder vs du? I have just noticed that for some of my directories on an external disk there is a huge difference in calculated size depending on whether I use the GUI Finder or du (or rather du -h). Using Finder on this directory I get 145 GB, whereas du gives me 135 GB. That is a difference of 10 GB! Checking another directory I (on my local machine) I get 41 vs 43,7. So there seems to be almost a 10% difference here. Can anyone explain this?
I'm not entirely sure but 145GB is exactly 135 GiB so I think Finder gives result with decimal prefixes while du uses the binary ones.
See this article