League of Legends is a online video game developed by Riot Games. The ratio of kills, deaths and assists you have faced in the game is said as KDA (kills, deaths, assists) ratio. This is an online calculator to find the KDA ratio with the number of kills, deaths and assists. A good and perfect ratio will depend on the game you play.
You are playing the league of legend game and if you have 6 kills, 4 deaths and 3 assists
KDA Ratio = (K+A) / Max(1,D)
= (6+3) / Max (1, 4)
= 2.25 is the KDA ratio