Scripting to find the size of the folder

Will any body help me by writing a script in unix to the find out the size of the Main folder which has some 5 to 6 subfolders which in turn has some file in each of these subfolders

regards
victorvvk

man du

Cheers
ZB

Thank You ZazzyBob

I have been waiting since long time.Thank you very much for answering me

Victor