The command du "summarizes disk usage of each FILE, recursively for directories," e.g.,
du -hs /path/to/directory
-his to get the numbers "human readable", e.g. get140Minstead of143260(size in KBytes)-sis for summary (otherwise you'll get not only the size of the folder but also for everything in the folder separately)
As you're using -h you can sort the human readable values using
du -h | sort -h
The -h flag on sort will consider "Human Readable" size values.
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
