Binomial Probability Calculator
Find exact-success probability and cumulative probability for independent binary trials.
Your result
MATHEnter your values and select calculate.
On this page How it works & practical examples
How to use the Binomial Probability Calculator
All trials must have the same success probability and be independent. The cumulative row is the probability of at most the entered number of successes.
The calculation
Worked example
For ten independent trials at 50% success probability, exactly three successes have 11.7188% probability.
Assumptions and limits
The probability model does not establish independence or estimate the success rate from data. Supports at most 1,000 trials; very small probabilities may round to zero in the display.
Common questions
Which inputs should I use?
All trials must have the same success probability and be independent. The cumulative row is the probability of at most the entered number of successes.
What does the result exclude?
The probability model does not establish independence or estimate the success rate from data. Supports at most 1,000 trials; very small probabilities may round to zero in the display.