How to predict Phorum size (mb)?

[Anon]

I am considering adding Phorum to my site but am unsure if I will bang up against my current hosts 20 megabyte limit.
How can I predict the size?
Start with the size of the base program and then add up the kb's based on expected number of letters, words, sentances etc...?
Or is there other overhead & bloat to consider? Are there any rules-of-thumb for say a site with 10 posts or 100 posts per day?
Thx, Doug

[Anon]

My phorum setup has ~600 posts in four forums. The entire mySQL database (directory) takes up 705Kb. So about 1k per post should be a good rule of thumb. Of course this doesn't count the php files, php program, apache, mySQL and everything else required to make it work.