The command du “summarizes disk usage of each FILE, recursively for directories,” e.g.
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)
List of all the folders in /path/to/folder and their sizes.
du -h --max-depth=1 /path/to/folder
List from smallest to largest.
du -h --max-depth=1 /path/to/folder | sort -nk1