Project Duration Estimator (PERT)
Calculate project duration using PERT three-point estimation with optimistic, pessimistic, and most likely scenarios
About this calculator
The Project Duration Estimator using PERT (Program Evaluation and Review Technique) helps project managers calculate realistic project timelines by considering three scenarios: optimistic, pessimistic, and most likely durations. This three-point estimation method provides more accurate project scheduling than single-point estimates by accounting for uncertainty and risk. PERT analysis weighs the most likely scenario four times more heavily than optimistic and pessimistic estimates, delivering statistically sound duration predictions that improve project planning and resource allocation.
How to use
Enter your optimistic time estimate (best-case scenario), pessimistic time estimate (worst-case scenario), and most likely time estimate for your project or task. The calculator applies the PERT formula: (Optimistic + 4×Most Likely + Pessimistic) ÷ 6 to generate the expected duration and standard deviation for better project planning.
Frequently asked questions
What is the PERT formula and how does it work?
PERT uses the formula (O + 4M + P) ÷ 6, where O is optimistic, M is most likely, and P is pessimistic time estimates, providing weighted average duration.
How accurate is PERT estimation compared to single-point estimates?
PERT is significantly more accurate as it considers uncertainty and multiple scenarios, reducing estimation bias common in single-point project duration predictions.
When should I use PERT estimation for my projects?
Use PERT for complex projects with high uncertainty, multiple dependencies, or when accurate timeline predictions are critical for stakeholder management and resource planning.