Negative Binomial Distribution Calculator
Result
Negative Binomial Distribution Calculator — free online calculator.
Formula
- Negative Binomial Distribution Calculator calculates its result from Required Successes (r), Probability of Success (p), Trial Number (k). It uses the formula P(X=k) = C(k−1, r−1) × p^r × (1−p)^(k−r) · μ = r/p · σ² = r(1−p)/p². Change any input to recalculate the result instantly.
- The main inputs are Required Successes, Probability of Success, Trial Number. Enter them in the units and format shown in the calculator.
- Keep comparable quantities in compatible units whenever the formula combines or compares them.
- Changing any input above recalculates the result with the same calculation engine used by this page.
Example: Negative Binomial Distribution
- Required Successes: 3
- Probability of Success: 0.4
- Trial Number: 7 k
Negative binomial pmf: C(k−1,r−1)p^r(1−p)^(k−r). Cumulative probability through trial k; mean r/p and variance r(1−p)/p².
Sample result: Calculating…
Frequently asked questions
What does the Negative Binomial Distribution calculate?
Negative Binomial Distribution Calculator — free online calculator.
Which values should I enter?
Enter Required Successes, Probability of Success, Trial Number using the units and format shown beside each field.
What formula does this calculator use?
The calculator uses the following relationship: P(X=k) = C(k−1, r−1) × p^r × (1−p)^(k−r) · μ = r/p · σ² = r(1−p)/p².
Why might my result differ from another source?
Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.
Does the result update automatically?
Yes. Changing an input updates the result using the same calculation engine shown on this page.