101 with nearly proper output, besides printing the fraction for K and M as well. df -k|perl -pale'map{my$i;$_=sprintf"%6.1f%s",$_/1024,qw(K M G)[++$i]while$_>1024}@F[1..3];$_=join"\t",@F' Update: another 4 off, so we're at 97. df -k|perl -pale'map{$_=sprintf"%6.1f%s",$_/1024,qw(K M G)[++$"]while$_>1024}@F[1..3];$"="\t";$_="@F"' Update: and an examplary solution using awk (sed is not the tool for this job): df -k|awk '{OFS="\t";CONVFMT="%6.1f";for(i=2;i<5;i++){while($i>1024)$i=$i/1024}print}' It's missing several things, so I didn't bother counting characters. On the other hand, for this small job, especially if used frequently, I'd prefer something like this over the Perl solution simply for efficiency - awk is pretty nimble compared to perl, which is important when working interactively.

Makeshifts last the longest.