While using df

Solaris
df -h is the command to display available disk free space in bytes
e.g.,
$df -h
Filesystem size used avail capacity Mounted on
/dev/md/dsk/d84 3.9G 136M 3.8G 4% /var
swap 6.6G 992K 6.6G 1% /tmp
/dev/md/dsk/d101 20G 7.8G 12G 41% /software

Equivalent df in AIX
df -g