Input Mode: Fraction

Enter a numerator and denominator to specify the probability. For example, “1 / 100” equals a 1% chance per draw.

Input Mode: Percent

Enter the probability directly as a percentage. For example, entering “1” means a 1% chance per draw.

Calculation Mode: At Least Once

Calculates the probability of winning at least once across N draws, and the probability of getting no wins at all. Great for calculating gacha or lottery odds.

Calculation Mode: Consecutive

Calculates the probability of winning on every single one of N consecutive draws. Useful when all attempts must succeed.

Calculation Mode: Min. Draws

Calculates the minimum number of draws needed to reach a target win probability (e.g., 80%). Enter a price per draw to also see the estimated total budget.