Probability

These probability tools take a single-trial success rate (a drop rate, for example) together with a number of attempts and calculate the odds of hitting your target outcome, along with the expected number and median number of tries needed to get there.

Use them to simulate how much a gacha pull might cost you before you spend a cent, or to build a more intuitive feel for probability in the classroom.

Gacha Probability Calculator (Expected Value & Pity Simulator)

Gacha probability calculator: enter your drop rate, number of pulls, and pity counter to get exact binomial odds, expected draws, median draws, and expected cost.