How do you calculate efficiency when doing AG?
Primary 1: ESB
Primary 2: Empty
Secondary 1: Empty
Secondary 2: Empty
Secondary 3: Empty
Up next: Common ESB, porter, probably some Belgian
Here is John Palmer's explanation: http://www.howtobrew.com/section2/chapter12-5.html
Bugeater Brewing Company
I'll second the using a program to do the calculation. It's fun to do it once or twice by hand..... but a lot easier to let ProMash tell you how well you've done.