Task Estimation

Enter optimistic, most likely, and pessimistic time estimates for your task.

PERT Estimates

Best-case scenario

Most realistic

Worst-case scenario

Expected Time
4.3
hours
Std Deviation
1.0
hours
68% Range
3.3 - 5.3
hours
95% Range
2.3 - 6.3
hours

Distribution

Best Case
1.3 hours
Expected
4.3 hours
Worst Case
7.3 hours

Confidence Intervals

68% confidence~1σ
Most likely outcome range
3.3
5.3hours
95% confidence~2σ
High confidence range
2.3
6.3hours
99.7% confidence~3σ
Maximum range
1.3
7.3hours

How PERT Works

Expected Time: Calculated as (O + 4M + P) / 6, giving more weight to the most likely estimate.

Standard Deviation: Measures uncertainty, calculated as (P - O) / 6.

Confidence Intervals: Statistical ranges showing probability of completion within timeframes:

  • 68% confidence (±1σ): Most likely outcome range
  • 95% confidence (±2σ): High probability range
  • 99.7% confidence (±3σ): Nearly certain range