bash-3.00$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 19G 0 100% /
/dev/sda1 99M 15M 80M 16% /boot


I mean, 20 == 19 right? And 80 + 15 = 99. Awesome. The ‘man df’ page says ‘-h’ is for ‘human readable’. I guess the math really needs to be dumbed down for us humans to understand it.