PERT Estimate Calculator
Calculate weighted duration from optimistic, most likely, and pessimistic estimates.
Inputs
days
days
days
Results
Expected Duration (PERT)
10.8 days
Standard Deviation2.5 days
Variance6.3
Range (Low)5.8 days
Range (High)15.8 days
Total Range10 days
Risk Factor (CV)23.1%
How to Use This Calculator
- Enter the optimistic (O), most likely (M), and pessimistic (P) duration estimates for the task.
- The calculator computes the PERT weighted average: (O + 4M + P) / 6.
- Review the PERT estimate and the standard deviation (P - O) / 6.
- Use the standard deviation to calculate confidence intervals for schedule risk analysis.
- Sum PERT estimates across critical path tasks to get an overall project duration estimate.
Ad Placeholder
Related Calculators
Ad Placeholder