From brokenpoet.org wiki

This will give you a report which will show the username, the amount of files they have in their home directory and also the size of their home directory - like this:

User          Count     Size
----------------------------
aguyhere        320      14M
begone          147     1.1M
careless         36     312K

Simply copy this command and paste it:

printf "User          Count     Size\n";echo "----------------------------";\
for user in $(cat /etc/domainusers |cut -d':' -f1|sort);do count=$(find /home/$user -type f|wc -l);\
size=$(du -hs /home/$user|awk '{print $1}');printf "%-9s%10s%9s\n" $user $count $size;done