This calculator finds the KDA ratio for a video game, which measures the sum of kills and assists relative to the number of deaths. There are two basic equations to calculate KD for any game. These include: KDA = (kills + assists) / deaths. KDA (kill death assists) ratio is a measure of the total number of kills and assists relative to the number of deaths that a player accrues in a video game. KD (kill death) ratio formula: KD = kills / deaths.