If you want to find the largest files within your Linux system, see this post instead. Here is the command to find the top 20 largest folders in a given directory and print their size in a human readable format (eg. 2.4M, 24G).
# the full command du -hx path/to/your/directory | sort -hr | head -20
Find the 20 heaviest directories in your ~/Documents directory and print their human readable size
# replace with the directory you want to scan sudo du -hx ~/Documents | sort -hr | head -20
Find the top 10 heaviest directories in your entire system and print their human readable size.
# This might take a long time to execute, because you are scanning your entire system sudo du -hx / | sort -hr | head -10
You can try each of the following commands for yourself to see the results.
# find all directories within your current file system (-x) and print their size in a human-readable format (-h) du -hx ~/Documents
# sort by human-readable format (-h) so 2G will be bigger than 50k even if 2 < 5, and reverse the order (-r) sudo du -hx ~/Documents | sort -hr
3- head -20
# keep the first 20 lines (-20) sudo du -hx ~/Documents | sort -hr