du

 # To sort directories/files by size:
du -sk *| sort -rn

# To show cumulative human-readable size:
du -sh

# To show cumulative human-readable size and dereference symlinks:
du -shL

# Show apparent size instead of disk usage (so sparse files will show greater
# than zero):
du -h --apparent-size

# To sort directories/files by size (human-readable):
du -sh * | sort -rh 

# To list the 20 largest files and folders under the current working directory:
du -ma | sort -nr | head -n 20

# To include hidden files and directories:
du -sh .[!.]* *