Drop Rate

OSRS Drop Rate Calculator

1 / 512 · 0 KC

Inputs

Every kill is an independent 1/N roll. There is no pity timer and no “due” mechanic in OSRS.

Kills for a 50% chance

355KC

At 1 / 512

Add your kill count on the left to see the full distribution of likely outcomes.

Chance of at least one, by kill count

90%50%
0 KC2,356 KC

Kill count milestones

50% chance

355 KC

90% chance

1,178 KC

95% chance

1,533 KC

99% chance

2,356 KC

Learn more

How it works

Same binomial model as the dry calculator, with extra views for exactly X and X or more drops.

Important mechanics

  • P(X = k) uses a log-space binomial coefficient so large kill counts stay numerically stable.

Frequently asked

What if I want two uniques?

Set desired quantity to 2. 'X or more' is the chance of at least that many successes.

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