I'll use "df -H" instead. Flag "-g" uses "1-Gbyte blocks" to calculate disk spaces. However, Apple has long since moved away from it to "Giga-byte". If you use "-g", you'll find the numbers shown by the command not matching the numbers in Disk Utility and Finder, which can be confusing to some users. By using "-H", it'll make sure the numbers are matched within the OS.