Gacha / Loot Box Probability Calculator
Calculate the probability of getting at least one win given a pull rate and number of attempts. Shows cumulative probabilities and pulls needed to reach 50%, 90%, and 99% targets.
%
pulls
Probability of at least 1 win
26.3%
10 pulls at 3% win rate
Pulls needed to reach target probability
50% target23 pulls
80% target53 pulls
90% target76 pulls
95% target99 pulls
99% target152 pulls
Cumulative probability by pull count
| Pulls | Cumulative chance |
|---|---|
| 1 pulls | 3.00% |
| 5 pulls | 14.13% |
| 10 pulls | 26.26% |
| 30 pulls | 59.90% |
| 50 pulls | 78.19% |
| 100 pulls | 95.24% |
| 200 pulls | 99.77% |
| 300 pulls | 99.99% |
| 500 pulls | 100.00% |
How to Use
Enter the win rate
Use the slider or type the per-pull win rate (%) shown in the game's drop rate table.
Set the number of pulls
Enter how many pulls you plan to make. Use the slider (1–500) or type directly for larger numbers.
Read the results
The large number shows the probability of winning at least once. The table on the right shows cumulative probabilities at common pull counts.
FAQ
- About 26.3%. The formula is 1-(1-0.03)^10 ≈ 0.263. There is still a 73.7% chance of getting nothing in 10 pulls.
- The formula is ceil(log(0.5) / log(1-p/100)). For a 3% rate, that is about 23 pulls. Use the 'pulls needed' panel to see the number for 50%, 80%, 90%, 95%, and 99%.
- Yes, this calculator assumes each pull is an independent event with the same fixed probability. Pity systems (guaranteed drops after N misses) are not modeled here — the actual probabilities for those are higher.
- Mathematically, 1-(1-p)^n approaches 100% asymptotically but never reaches it. In practice, games implement pity mechanics (hard pity / soft pity) to guarantee a reward after a certain number of pulls. Check the game's official rules for pity details.