Gacha & Drop Probability Calculator

Turn a drop rate and a pull count into the real chance of at least one drop.

Estimate the real odds of getting an item from gacha, loot boxes, or random drops over any number of pulls.

Inputs

Drop rate per pull (%)Chance of the item on a single pull (e.g. 2% for a 1/50 drop).

Number of pulls

Result

P(≥1 drop) = 18.29%

Chance of no drop81.71%

Chance of ≥1 drop18.29%

Expected drops0.20

Each pull is independent: the odds of at least one success after 10 pulls is 1 − (1 − rate)^pulls. Past pulls do not change future odds, so "due" drops are a gambler's fallacy unless the game has explicit pity.

Models independent draws only. Games with pity or soft-guarantee systems perform better than shown — check the game's stated rates.

Reading drop odds without the gambler’s fallacy

Scenario: a banner says a 5-star has a 2% drop rate. You do 10 pulls — what are the real odds you get at least one? Most players wildly overestimate this.

Example: at 2% per pull over 10 pulls, P(at least one) = 1 − 0.98^10 ≈ 18.3%, not 20%. Over 50 pulls it climbs to ≈ 63.6%. The calculator shows the true curve.

Boundaries: this models independent draws only. Many games add pity or soft-guarantees that improve odds after a dry streak — those are not captured here, so real rates are often better than shown. Always check the game’s published rates.

FAQ: does a 2% rate mean a drop every 50 pulls? No. Each pull is independent; “due” drops do not exist without pity. The expected number of drops after 50 pulls is 1, but you could get zero or several.