Gacha Probability
Cumulative pull chance with pity floor.
What it does
Computes the cumulative probability of pulling at least one SSR after N pulls, with optional pity (guaranteed drop at fixed pull count). Used by every modern gacha designer.
How to use it
Enter base SSR rate (e.g. 0.6%), pity floor (e.g. 90 pulls), and the pull count you want to evaluate.
Designer tip
Pity floors below 0.5% × 2 are punishing. Anchor pity so a "spender" reaches it once per banner — that's the psychological sweet spot.
Open the calculator
Open it at /calculators/gacha. Calculators run entirely in your browser — no credits charged.
Ready to try it?
Open the generator →