Binomial Probability Calculator
Binomial probability calculator: P(X = k), P(X ≤ k), P(X ≥ k) and the mean and standard deviation for n independent trials.
P(X = k) = n!k!(n − k)! pk(1 − p)n − k
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
Use it when each trial has two outcomes with the same success probability p, such as coin flips or pass/fail tests.
Frequently asked questions
Exactly 3 heads in 10 coin flips?
P = 0.1172 (11.7 %).
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