The KO Chance Calculator is a tool used to calculate the exact chance of a combination attack KOing a Pokemon (2 or more attacks). It can also be used to get more precise % to KO chances than the damage calculator currently provides. Results are given as a percent, as a raw fraction, and as a simplified fraction. This is most practical in Doubles play, but perhaps it has other applications in singles as well (e.g. the odds of a Pokemon being KOed when switching into a resisted attack + being hit by some other attack).
Download here: https://github.com/DaWoblefet/KOChanceCalculator/releases