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Three-Point Contingency Calculator

Calculate a PERT expected value, standard deviation and approximate planning range.

How to use this calculator

Three-point estimating can reduce the false certainty of one number. The PERT expected value weights the most-likely value four times, while the range indicates how widely the three inputs are spread.

Enter three ordered values and calculate.

The displayed low/high values use expected value ± two simple PERT standard deviations. This is not a full probabilistic risk simulation and does not imply a guaranteed confidence level.

Interpret the result

Review the result as a scenario, not a verified estimate. Test the assumptions that matter most, record the date and currency basis, and reconcile the calculator with the project’s formal estimate and approval process.