EN

drop chanceClassic tool

Drop Chance Calculator

Estimate your cumulative chance of getting at least one drop after repeated attempts and see how many runs it may take.

Use this drop chance calculator to estimate the cumulative probability of getting a rare item after repeated runs, pulls, chests, bosses, mobs or matches. It answers a common gaming question: after doing the same activity many times, what is the real chance that the item still has not dropped.

Enter the drop rate per attempt and the total number of attempts. The tool returns the chance of getting at least one drop, the chance of getting nothing at all, the expected number of drops and the rough point where your cumulative chance passes 50%.

The math assumes independent attempts with a fixed rate every time. If the game uses pity, soft pity, progressive odds, multiple loot rolls or temporary event boosts, treat this as a fast baseline rather than a full simulation of the drop system.

The calculation assumes each attempt is independent and that the drop rate stays fixed across runs.

SummaryFill in the drop chance and attempts to calculate the cumulative probability.
Chance of at least one drop—
Chance of no drop—
Expected quantity—
Attempts for ~50%—
Applied formula—

Use clear inputs to get a more useful result.

How cumulative drop chance works

A 2% drop rate per attempt does not become 100% after 50 runs. The correct approach is to calculate the chance of failing every attempt first, then convert that into the chance of at least one success.

When the estimate stops being exact

Games with pity systems, guarantees, changing loot tables or time-limited bonuses break the fixed-rate assumption. In those cases, this calculator is still useful as a baseline, but not as a full model of the game.