Honestly, it's such a crapshoot. i've seen people jump levels only to get a 4% bump because they were already at the ceiling for their old grade. if you're sitting mid-band or lower, you'd expect something more meaningful - maybe 8-12%.
Timing also plays a bigger role than people admit. if you just got a hefty raise three months ago, don't be surprised if the promotion itself is a token gesture. And then there's the whole "is this actually a different role or just a title change" question - half the time it's the latter.
From what I've seen across agencies and in-house teams, manager to senior manager tends to land between 5% and 12%, but it really depends on how hard you push. if you don't ask, you won't get