bdf -Pk | awk '
BEGIN {print "Filesystem Mount Point Total GB Avail GB Used GB Used"

   print "--------------- --------------- ---------- ---------- ---------- -----"}

END {print ""}
/dev/ {
printf ("%-15s %-15s %10.2f %10.2f %10.2f %4.0f%n",$1,$6,$2/1024/1024,$4/1024/1024,$3/1024/1024,$5)
}'