I made a Damage Calculation tool that is able to accurately predict all important damage figures about any ability applied on any target(as long as both of them are level 40).
Link to the spreadsheet: Damage Calculator
The results can at most be 1 or 2 damage points off due to the game rounding down numbers at various points in the actual calculation.
To use it, you have to manually plug in a handful of required stats for the attacker, the target and the ability used.
- The attacker stats can be found by using the .getstats command in game
- The target's stats can either be calculated manually (e.g. from killboard) with assumptions regarding tactics and renown points. Alternatively you can take them from the "Enemy Templates" sheet where I have compilled some indicative stats for engame wb builds of each role.
- The ability information can be easily calculated for any skill by following the 11 step process described in the "How to fill in the Ability section" sheet (should take around a minute for one ability)
Here is an example of the results the tool provides:

(The guard/detaunt and challenge are dynamic toggles to see how the damage changes if either or both of them are applied)
If you think anything is missing or have any other questions/suggestions then please leave a comment.
Enjoy