RAL's Program Evaluation Review Technique (PERT) Calculator

Enter your activity time estimates and calculate project probabilities.

1. Activity Calculation

Activity Optimistic Most Likely Pessimistic Expected Time Std. Deviation Variance Action

Total Expected Duration:

0.000

Total Variance:

0.000

Total Standard Deviation:

0.000

2. Project Probability (Z-Score)

Sum of Expected Time for all activities on the critical path.

Square root of the sum of Variance on the critical path.

The date you want to check the probability against.

Z-Score Result

N/A

Probability of Completion

0.00%

This is the chance the project will finish *on or before* the target time.

Standard Normal Distribution (Z-Score) Cumulative Probability Table

⚠️ **Note on Probability:** This calculator uses the standard JavaScript `jStat` library for the cumulative distribution function (CDF) to provide a precise probability estimate based on the calculated Z-score. The table above serves as a **manual reference** derived from standard statistical data.