About the Scenario Analysis Calculator
Best, base and worst-case scenarios with probabilities: expected outcome, spread and downside risk.
Also known as: scenario risk, best worst case, scenario planning calculator.
How to use this calculator
- Enter best case outcome, best case probability, base case outcome, base case probability and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
E = Σ outcome × probability
Worked example
Using the values pre-filled in the calculator above:
- Best case outcome = 150,000
- Best case probability = 25 %
- Base case outcome = 80,000
- Base case probability = 50 %
- Worst case outcome = -40,000
- Worst case probability = 25 %
the calculator returns:
- Expected outcome: 67,500
- Standard deviation: 68,328.25
- Chance of a loss: 25%