For shorter bunker shots I use the following:
Usually you will be in a 30-40% lie in a green-side bunker. I play the height adjusted distance x 1.33, plus 5 for full BS which you will want to have any chance of stopping the ball on Tourney/Champ greens.
Ex - 18yd, up 4', 30-40% lie
18 + 1(for up 4') x 1.33= 25.27 , plus 5 = 30.27
I use a Cleveland 64 degree wedge which has a 60 yd max. So I would hit it at around 50%.
Keep in mind the green break and speed after the ball will land and adjust accordingly.
Note: If you short-sided yourself and don't have any green to work with you will most likely need to play extra yardage and put the ball past the hole. Much better then chipping your next shot from the rough or fescue.