Check Disk / Folder / File Size

Check disk size

df -h .

(base) tk@a25:/rscratch/tk/Desktop$ df -h .
Filesystem                        Size  Used Avail Use% Mounted on
10.11.49.77:/export/zfs/rscratch  115T  101T   15T  88% /rscratch

Check Current Folder Size

du -sh .

(base) tk@a25:/rscratch/tk/Desktop$ du -sh .
88G     .

To list children sizes, do

du -ch .