Original damage calculator by AMF. Stat calculator, RNG and modifications to damage calculator by Phoenixsong. Currently optimized for Gen V items and formulas but can also be used for Gen IV damage calculation; use the options for Selfdestruct/Explosion and Simple only when calculating Gen IV damage and ignore them for Gen V. (For Simple in Gen V, just double the change in Atk/Def stage, then enter the new stage in the appropriate field.)
Thanks to X-Act and Peterko from Smogon for the Gen IV damage formula. The modifications I made to account for Gen V should be accurate but may change pending further research. Caveat emptor.
Mouse over the fields for an explanation.