The du command displays disk usage for each file or folder. You can use this command to find the size of a folder in Unix or Linux. Below are some examples.
du -s /home/andrew
19112204 /home/andrew
The above command displays the size of the folder /home/andrew. The option -s displays a summarized size, or total size. If you do not use the -s option then it will list the size of all files and folders in the path /home/andrew recursively.
du -sh /home/andrew
19G /home/andrew
Adding the -h option displays the size in human redable format.
For more detailed information and option for the du command, use the following command.
man du