BrewCalc has been updated. It now has a sheet that will scale recipes up/down according to your specifications. The first sheet ('OG, IBUs, ABV%, etc.') is a bit cleaner as well. I've hidden the ugly results of the Tinseth utilization calculations as to cut down on distraction.
I'll probably be updating BrewCalc in the next week or so with some fun new stuff. In particular, I'm working on making the Points per Gallon numbers adjustable by the user without futzing a whole lot with the calculation in J13. I'll post once I get it up and running.