Binomial Probability
A binomial model describes a fixed number of independent trials with the same success probability on each trial.
Binomial Probability
Probability · 3 inputs
How to use this calculator
- Enter trials in count.
- Enter successes in count.
- Enter success probability in 0–1.
- Select Calculate and keep the output unit with the answer.
Before you use the answer
Choose the reference quantity before interpreting the number. A ratio, a percentage and a percentage-point difference may use the same observations while answering different questions. For recorded data, keep the original values beside the summary so an unexpected result can be traced back to its inputs.
Successes must not exceed trials. Changing probabilities or dependent trials require a different model.
Does it save my inputs?
No calculation history is stored by this website. The calculator works locally in your browser. See the privacy policy for hosting and contact details.
Why might a result be approximate?
Measurement uncertainty, ideal-model assumptions and floating-point rounding can all matter. Displaying more digits does not improve the original measurement.
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Independent Joint Probability
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The complement of no successes gives the chance of at least one success.
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An event and its complement cover all outcomes without overlap.
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