damage = (0.2*((0.8*RECHARGE)+1.8))/(AREA MOD)
endurance = Damage * 5.2
Area Mod = 1 + (0.15 * radius) - (0.011 * radius/6) * (360 - arc)/5
Damage is the "damage scale", that gets multiplied by the appropriate ranged or melee modifier for the AT/level to get the final damage.
For a single target attack, the Area Mod just works out to 1. For AoE's, the larger the area that it can hit, the larger the Area Mod gets, making the damage lower.
Now I better get out of here before the regulars run me out, seeing as how I'm only here because Castle posted about buffs. 
I don't know if this belongs in General, but this is the forum where I heard about the equations in the first place, in one of the flamefest Psi Assault threads. Someone had said that according to X equation Psychic Shockwave would require 50 endurance to use based on the dev equations. They also said a number of powers were outliers, but generally only in a range of about 30%
Can anyone tell me the equations used for determining endurance etc.? I was trying to figure out if the non-Shockwave attacks in psi assault are also outliers, but in a bad way.
Thank you
Active (Freedom): Setna (Ice/Psi Dom), Arram (WP/KM Tank), Tesmiel (Elec/SS Tank), Astredax (Robot/Dark Mastermind), Operative Vidali (melee fortunata)
Retired (Virtue): Gaav (Inv/EM Tank), Baqra (Fire/SS Tank)