I recently discovered the calculator on Beersmith and just started to use the calculator. I have 5 batches fermenting now, yea, that is a lot, but I wanted to do as much brewing before real winter set in and use up all my base grains before the new bulk bags came in. I will be able to give an update in about a month. Ive got an IPA, Stout, Wee Heavy, Smoked Porter and a Vienna Lager. There is a fairly decent amount of loss in the acid as the hops age as indicated by the calculator so its either going to be correct or way over hopped beer.