Disk usage

The command du "summarizes disk usage of each FILE, recursively for directories, example:

du -hs /path/to/directory

• -h is to get the numbers "human readable", e.g. get 140M instead of 143260 (size in KBytes)
• -s is for summary (otherwise you'll get not only the size of the folder but also for everything in the folder separately)

If you only use -h, you can get the size of each file, which you can sort by size:

du -h | sort -h

If want to avoid recursively listing all files and directories, you can supply the --max-depth parameter to limit how many items are displayed. Most commonly, --max-depth=1

du -h --max-depth=1 /path/to/directory

source: https://askubuntu.com/questions/1224/how-do-i-determine-the-total-size-of-a-directory-folder-from-the-command-line