And for my 3000th post, of course the obligatory Fret Calculator should grace this thread...

Stew Mac's is great but doesn't give you a print out that you could use to cut your frets....not that you can rely on a printer to reproduce to scale.
https://www.stewmac.com/FretCalculator

and then theres Fret2Find for those who really understand what's going on with the fretboard (includes multiscale).

http://www.ekips.org/tools/guitar/fretfind2d/