Formula
PERT estimate = (optimistic + 4 × most likely + pessimistic) ÷ 6. Buffer increases with complexity and expected interruptions.
How to use this calculator
Enter optimistic, likely, and pessimistic estimates. Add complexity and interruptions to get a more realistic time block and risk label.
What this calculator includes
- Uses a standard weighted estimate instead of a guess.
- Adds buffer for complexity and interruptions.
- Shows uncertainty range.
- Helps prevent underestimating tasks.
Tip: Use conservative inputs when planning deadlines or workload. A calculator is most useful when it prevents overcommitment, not when it only confirms an optimistic plan.
FAQ
What is a PERT estimate?
The Task Estimate Calculator helps you convert rough productivity estimates into clearer planning numbers. Results are directional, so use them as a decision aid rather than a fixed rule.
Why use optimistic and pessimistic estimates?
The Task Estimate Calculator helps you convert rough productivity estimates into clearer planning numbers. Results are directional, so use them as a decision aid rather than a fixed rule.
How much buffer should I add to a task?
The Task Estimate Calculator helps you convert rough productivity estimates into clearer planning numbers. Results are directional, so use them as a decision aid rather than a fixed rule.
What causes estimation risk?
The Task Estimate Calculator helps you convert rough productivity estimates into clearer planning numbers. Results are directional, so use them as a decision aid rather than a fixed rule.
Can I use this for project planning?
The Task Estimate Calculator helps you convert rough productivity estimates into clearer planning numbers. Results are directional, so use them as a decision aid rather than a fixed rule.