To check storage space usage, type:
This utility will show a table explaining how much space has been used in your storage devices and partitions as well as how much is remaining.
If you want to know how large a directory is, you can find out with du:
du -sk /usr/pkg
The -s option asks for the sum or total space used. The -k option causes the result to be shown in kilobytes (instead of 512-byte blocks).