How to check directory size in Linux/Ubuntu via command line

(Note: It works for MacOS too)

If you need to check the size of a directory on your computer, it is better to use special tools such as ncdu, dust or tree. I prefer ncdu - it does the job!

But, it is more common to use CLI if you work with a remote machine, often without a permission to install additional software into it. Then pre-installed tools come to rescue - du. See how I use it below.

du -h .

This gives us a list of all directories and subdirectories in current directory. That's not what we meant, huh?
Note: The dot character can be replaced with a relative or absolute directory path.

du -sh .

The option -s stands for summary result. Now we see the entire folder size. But still, how to see each subfolder individually?

du -sh ./*

# or just:
du -sh *

Here it is! Now we see the size of each subfolder of 1st level.

du -sh .[^.]* *

Then you might want to see hidden folder and files too. A bit more complicated with regular expression.

Moreover, usually we would like to see result sorted, the largest elements come first:

du -sh * | sort -rh

The sort options -r is for reverse, and -h is for natural/numeric sort order.

These are just the basics, please share your favourite method in the comments.