I noticed a tiny error in the Stats_Calc sheet that was giving me one more stamina than expected. For reference here is the character I was using to check this:
http://www.wowarmory.com/character-shee ... &n=ForsyteNow the spreadsheet gives me 1787 Stamina rather than the expected 1786. What I found is that the game rounds the stamina two separate times, once for base stamina and toughness and once for stamina from gear and buffs. When I take (base+toughness+gear)*1.08*1.06, I get 1787 like the spreadsheet gives. If, however, I use the formula [(base+toughness)*1.08*1.06]+[gear*1.08*1.06] (I am using the square brackets here to mean the greatest integer/floor function), I get 1786 as the armory and client show. I'm assuming that stamina from buffs will be added to the second half as they show as "green" in the client tooltips. Thus, I think the correct formula for Stats_Calc!B17 should be =FLOOR(SUM(C17,H17)*I17*J17*K17, 1)+FLOOR(SUM(D17:G17)*I17*J17*K17,1)
On another note, I also noticed that the human base health seems to be off by 20 at level 80 (24614-17680=6934 base health w/o stamina)