This is what Bungie stated about KDR vs. KDS regarding all their previous game releases including the HALO franchise: (if bungie had changed their ways/calculation methods specifically for destiny I would hope they would inform their player base as KDS is a broadly used term in FPS gaming) I am not yet able to explain why the sum does not add up for you, however every bit of (official) info confirms the "how many kills you have over the amound of deaths you have". Kill-Death Ratio is a term used to define how many kills a player gets before they die each time they spawn. A K/D ratio is kills divided by deaths. For example, if a player gets 10 kills and 5 deaths in a given game, they have a 2 K/D ratio. It means they got 2 kills before they died each time they spawned (on average). In other words - for every 2 kills they got, they died once. K/D ratio is not to be confused with K/D spread. K/D spread is a player's (or team's) total kills, minus their deaths. K/D spread is a good metric for single games, while K/D Ratio is a more appropriate metric for a player's career. The reason being is that the more kills a player gets, the less useful K/D spread becomes. For example, a player has 500,000 kills and 470,000 deaths; a spread of +30,000, yet their K/D is close to average. The more a player plays the game, the less useful and less recognisable the K/D spread metric becomes. K/D ratio on the other hand begins to stay fixed the more a player plays, and is much more useful long-term. The average Halo player's K/D ratio is exactly 1.00 (excluding death by suicide or betrayal), as every kill results in a death. An under 1.00 K/D ratio means a player is dying more than they are killing, whereas an over 1.00 K/D means a player is killing more than they are dying.