original gravity by grain bill, weighted question

I understand there are alot of things to factor in such as efficiency, water, modifacation, etc. but what is the easiest way to calculate original gravity,gravity points, plato, balling or brix from the grain bill? I dont have beersmith or any other programs, I am just wondering if any one has an easy way? I have a 10 gallon fly sparge set up, 2 gott style coolers for the hlt, mash tun. My next purchase is going to be a refractometer and a hydrometer (just broke my old one i while sanatizing) so also how should i calibrate these?

...Beersmith?

Seriously, if you can, download the trial or download something like Qbrew--free, quick to download, and does it all for you.

There are many programes for free to download/use on the internet, start with:
http://hbd.org/cgi-bin/recipator/recipator

Or try Qbrew.

I would recommend just typing the grain bill in to the recipator and see what you get, you just need to know your ballpark effeciency and your rough final gravity, all can be estimated.

There are also several spreadsheets available, a quick search will turn them up.

check out www.tastybrew.com

They have several spreadsheets there for calcs

take a look under my download section in my signature.. I made an excel sheet that has that in it