I actually developed a spreadsheet a while back where you could type in the radius at the nut and the heel, and it would tell you the radius at each fret and at the bridge. Or you could do it the other way, so for instance if you want a 10" nut and a TOM bridge left stock at 12", it would tell you that you'd need a 10-11.44" (iirc) compound radius neck to achieve that.
I don't have the spreadsheet any more but I could reimplement it in JavaScript and run it up as a webpage somewhere if anyone's interested.