Count favorable and total equally likely outcomes.
Statistics Calculator
Probability Calculator
Calculate an event probability, percentage, complement, and odds from favorable and total equally likely outcomes.
Instant answer
Formula breakdown
Browser-based
Mobile friendly
Interactive calculator
Enter your values
Use the example values or replace them with your own. Required validation happens before the calculation.
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Calculated answer
Result
Simple workflow
How to use the Probability Calculator
Follow these steps to get a reliable result and understand how it was produced.
Divide favorable by total.
View percentage, complement, and odds.
Understanding the calculation
For equally likely outcomes, probability is the fraction of outcomes that satisfy the event. The complement is 1−P.
P(event) = favorable outcomes ÷ total outcomesThe result panel substitutes your numbers into this relationship and shows the important intermediate values.
Common uses
- Games and classroom probability
- Risk explanations
- Basic event modelling
Accuracy tips
- Favorable outcomes cannot exceed total outcomes.
- This simple model assumes equally likely outcomes.
- Probability ranges from 0 to 1, or 0% to 100%.
Helpful answers
Probability Calculator FAQs
Important details about formulas, inputs, limitations, and result interpretation.
What is a complement probability?
It is the probability that the event does not occur: 1−P(event).
What are odds in favour?
They compare favorable outcomes with unfavorable outcomes.
Can favorable outcomes equal zero?
Yes. That represents an impossible event in the defined sample space.
Does this handle dependent events?
No. This tool handles a single equally likely outcome model.