df -k|perl -ape'map{while(1024<$_){$_/=1024;$i++}$i="%6.1f".substr"KMG",$i,1;$_=sprintf$i,$_}@F[1..3];$_=join"\t",@F,$/'
##</code><code>##

/dev/dsk/c0t1d0s1          1.2G  795.7M  382.2M 68%     /usr
/dev/dsk/c0t1d0s3        239.7M   43.5M  172.2M 21%     /var
/dev/dsk/c0t1d0s0        414.6M  182.8M  190.3M 49%     /home
##</code><code>##

df -k|perl -ape'map{while(1024<$_){$_>>=10;my$i++}$_.=substr"KMG",$i,1}@F[1..3];$_=join"\t",@F,$/'


Output:
/dev/dsk/c0t1d0s1       1G      795M    382M    68%     /usr
/dev/dsk/c0t1d0s3       239M    43M     172M    21%     /var
/dev/dsk/c0t1d0s0       414M    182M    190M    49%     /home