Gacha Pity Probability Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026The math behind gacha pull odds
Even a low per-pull drop rate accumulates meaningfully across many attempts - this calculator applies standard probability theory to find the chance of landing at least one success across a given number of independent pulls.
Worked example
For a 0.6% drop rate (a common 5-star base rate in several popular gacha games) across 90 pulls:
P(at least one) = 1 - (1 - 0.006)^90 = 41.82%
This result closely matches publicly discussed cumulative odds figures for real gacha games using similar base rates before any pity system kicks in - many games layer a guaranteed "hard pity" on top after a maximum pull count, which this pure-probability formula does not model, since it assumes purely independent draws throughout.