How to Use the No Pity Gacha Expected Pulls Calculator
This calculator helps you plan your gacha spending in games that use pure probability without a pity guarantee. Enter the item's drop rate and how many copies you need, and the calculator provides three key numbers: the average expected pulls, the 50% confidence pull count, and the 90% confidence pull count.
The expected value is simply target count divided by drop probability. For a 0.5% rate, you need an average of 200 pulls per copy. The 90% confidence number is the budget you should prepare to have a 9-in-10 chance of success — about 1.6 to 2× the expected value for a single copy. Use this as your safe spending cap before a session.
The calculation uses a normal approximation to the negative binomial distribution. For multiple copies, the approximation becomes more accurate as the target count increases.
Frequently Asked Questions
No — it means roughly 9 out of 10 players will succeed within that many pulls. The remaining 10% will need more. There is no absolute guarantee in a system without a pity cap.
Yes. Enter the boosted drop rate for the featured item during a rate-up event to see the adjusted expected and confidence pull counts.