df [OPTION]... [FILE]...
Show information about the file system on which each FILE resides, or all file systems by default.
Display values are in units of the first available SIZE from --block-size, and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables. Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).
SIZE is an integer and optional unit (example: 10M is 1010241024). Units are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB,... (powers of 1000).