Are there any good online damage calculators?

[Pika25]

I use it to calc damage when catching legendaries...

I used the marriland calculator (see my sig below) to calc damage on wild Shaymin (it is at level 30) with Pikachu's Grass Knot. My Pikachu has a Special Attack of 166 at Level 100 (which doubles to 312 with light ball). Shaymin's Sp.Def is around 80 or so at Level 30. I found out that Grass Knot roughly 3HKO's Shaymin. (But I didn't need Grass Knot, I just used a Quick Ball on the first turn...it was Snagged.)