So we are doing something crazy... We are going to kill our way through d&d 3.5 deities and demigods. We are using level 40 characters and I'm having trouble figuring out my damage. I should be dishing out damage equal to the unarmed strike of a level 41 monk (huge size)...everyone has agreed since we are killing gods the raw cap at level 20 is to be ignored... So how much damage is that?
You're kind of on your own with this.
Pathfinder caps out at L20 characters. There are no official rules for level advancement beyond that.
You'll need to work with your GM to figure this out.
You might want to consider either making these characters L20 with 10 Mythic Tiers, or using the OGL/3.5 rules for Epic-Level characters, and adapting them as best you can for Pathfinder.
Good luck.
[EDIT: Flagged for being in the wrong forum.]
If you were to follow the natural progression of the monk unarmed strike damage, it increases every four levels. Also, it seems to increase from d6 to d8 to d10 and then come back around to d6. Were you following that logic, this is what the damage dice would like all the way up to 41st level:
1. 1d6
2. 1d6
3. 1d6
4. 1d8
5. 1d8
6. 1d8
7. 1d8
8. 1d10
9. 1d10
10. 1d10
11. 1d10
12. 2d6
13. 2d6
14. 2d6
15. 2d6
16. 2d8
17. 2d8
18. 2d8
19. 2d8
20. 2d10
21. 2d10
22. 2d10
23. 2d10
24. 3d6
25. 3d6
26. 3d6
27. 3d6
28. 3d8
29. 3d8
30. 3d8
31. 3d8
32. 3d10
33. 3d10
34. 3d10
35. 3d10
36. 4d6
37. 4d6
38. 4d6
39. 4d6
40. 4d8
41. 4d8
From there, you can look to the natural attack FAQ to determine how the damage dice increase when going from Medium to Huge size. In this case, 4d8 becomes 6d8 at Large size and 6d8 become 8d8 at Huge size.
Mind you, as Haladir mentioned, the game doesn't support anything above 20th level with official rules, so this is just an extrapolation based on what we have available. i.e. This is unofficial and just for fun!
I like figuring stuff out like this, so I hope it's helpful!