Bash script to find average file size in a directory

If you want output in Kb


 ls -l | awk '{s+=$5} END {print "Average file size: " s/NR/1024 "k"}'
Average file size: 28683.4k

If you want output in MB

ls -l | awk '{s+=$5} END {print "Average file size: " s/NR/1024/1024 "MB"}'

Average file size: 28.0112MB

If you want output in GB

ls -l | awk '{s+=$5} END {print "Average file size: " s/NR/1024/1024/1024 "GB"}'

Average file size: 0.0273546GB