➗ Binomial Probability Calculator
Calculate the probability of exactly k successes.
Result
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How this calculator works
Calculate the probability of exactly k successes.
Formula
P(X=k)=C(n,k)pᵏ(1-p)ⁿ⁻ᵏ
Example
For 10 fair trials, exactly 3 successes is about 11.72%.
Frequently asked questions
What does the Binomial Probability Calculator do?
Calculate the probability of exactly k successes.
Are the results exact?
The calculator follows the displayed formula. Rounded display values may differ slightly from full-precision results.
Can I use negative or decimal values?
Most fields accept decimals and negative values when they make sense for the formula.
How should I check an important result?
Review the formula, verify your entries, and confirm high-stakes work with a qualified teacher or professional.