Smart format library conversion help

Hello,
I am attempting to consolidate my library onto one computer in the house then run the calibre server in order to access the books while on the network vice plugging in my Kindle or the wife's Ipad.

My issue is that I have some books in epub format, some in mobi format, and some in both format.

Is there a way to have calibre scan the library and convert smartly the books that exist in only one or the other formats so that every book exists as both in epub and mobi format?

Thanks,
J