Grab a cheap hydrometer next time you order or go to the LHBS. Five bucks will get it and it'll save you from math. Heck, message me your address n I'll toss one in the mail next time I get to the post office... I get a new one with each gropon I buy.
Might be a while though. I work third so...
"Woop Woop Mother fker.... Unless you're a base player, you cn.. fkin, move your ass on.. Cops.." Maynard