How to Use the Gacha Probability Table Calculator
Enter your pull rate (%) to instantly see how many pulls you need to reach 50%, 80%, 90%, and 99% cumulative probability of getting at least one drop. The formula is: pulls needed = ⌈log(1 - target) / log(1 - p)⌉.
Pity system: If your game guarantees a drop before a certain number of pulls (pity/ceiling), enter that number. Any threshold that exceeds the pity count will show the pity value as the effective cap, and entries beyond pity are flagged with ⚠️.
For very low rates (below 0.5%), the 99% threshold can be thousands of pulls — well beyond practical budgets. In those cases, pity is your real upper limit.
Frequently Asked Questions
At 1%, 63 pulls gives roughly a 47% chance — not a guarantee. You need about 458 pulls to reach 99% probability. If there's a pity at 200, that's your realistic guarantee threshold.
Yes. Any independent random event with a fixed per-attempt rate works with this tool — loot drops, crafting chances, or probability experiments.