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Single-Event Probability Calculator

Calculate probability from favorable and total equally likely outcomes.

Your inputs

Your result

Enter your information and select Calculate to see the result.

How this calculator works

Probability is favorable outcomes divided by total equally likely outcomes.

Change one assumption at a time to see which inputs have the greatest effect on the estimate.

Worked example

Rolling an even number on a fair die has probability 3/6, or 50%.

Limitations

This calculator is for educational use; verify important work independently.

Review this educational estimate against current quotes, official information, and your own budget before making a financial decision.