How to Use the Win Probability Simulator
Ever wondered how many times you'd win a gacha pull, a raffle, or any low-probability repeated event? Enter the win probability per trial and how many times you plan to try. The tool shows you the theoretical expected wins alongside an actual simulation so you can compare the math with real randomness.
How to Use
Enter the win probability per trial (%), the number of trials per set (up to 10,000), and how many times to repeat the simulation (up to 1,000). Click "Run Simulation" to see expected wins, simulation average, best/worst outcomes across all runs, and the probability of winning at least once.
Expected Value vs. Simulation
The expected value is a mathematical calculation: probability × trials. The simulation runs that scenario repeatedly with real random numbers. They should be close — but randomness means the simulation varies each run. More simulations → more stable average.
Frequently Asked Questions
Each simulation uses fresh random numbers, so results vary slightly. Increase the simulation count to get a more stable average that approaches the theoretical expected value.
A 5% drop rate over 50 tries: expected wins = 2.5. Simulate 1,000 times to see the realistic spread — including runs where you got 0 wins and runs where you got 8+.