Pokemon EV Calculator
This covers the arithmetic around effort values rather than the stat formula itself. Enter a target EV, the yield of the species you are defeating and whether you are carrying the Pokerus, a Macho Brace or a power item, and it returns the EVs per battle, the battles needed, what the vitamins add and how much overshoots the cap. A second tab checks a whole six-stat spread against the 510 total and the per-stat cap, and a third shows how many stat points a given EV investment actually buys at your level and the exact EV values where the stat goes up. Base EV yields come off the form because species data changes between games.