Probability Calculator
Calculate event, complement, combined, and binomial probabilities.
Probability
0.166666666667
- Percentage
- 16.66666667%
- Odds against
- 5
What this calculator does
Find common probabilities from outcomes or decimal probabilities, including independent events and exact binomial results.
Inputs and what they mean
- Calculation
- — choice value.
- Favorable outcomes
- — number value.
- Total outcomes
- — number value.
- Probability A / success
- — number value.
- Probability B
- — number value.
- Number of trials
- — number value.
- Exact successes
- — number value.
How to use it
- Enter the requested values.
- Choose the calculation mode when available.
- Review the result and supporting breakdown.
Formula
P(event)=favorable÷total; P(not A)=1−P(A); independent P(A and B)=P(A)P(B); binomial P(X=k)=C(n,k)p^k(1−p)^(n−k).
Worked example
Exactly 5 successes in 10 trials
At p=0.5, the probability is 0.24609375.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Common questions
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