Most guys would put a 14er on their wall. You figure a Lopes ears are about 6", so if you go twice that to the "url", then you got at least a 14er and probably more. Also, the prongs or "cutters" should stick out at least double the width of that horn. Capice? Big cutters, and 14"+ on length = wall hanger.
Me personally . . . I don't eat the horns anyway.
BTW . . . The width of spread does not add or detract from a lopes score.
Mulies, I'd stay closer to the ears being 20" tip to tip. Can vary though. But that way, if you always look for spread BEYOND the ear tips, then you got at least a 20"er and probably more. A 4X4 mulie past the ears is always a wall hanger. They never do have much for brow tines compared to white tails. Mass can be estimated by looking at the antler thickness (circumfrence) at the skull, and make sure it's at least as big around as the eyes. Bigger is always better. So length, # of tines, spread, and mass all add tp the scoring on a mulie.
Go to: http://www.boone-crockett.org/bgRecords/ScoringYourTrophy.asp?area=bgRecordsfor some interesting insight.