PERT Chart
Free Online PERT Chart Maker
What is a PERT Chart?
A PERT (Program Evaluation and Review Technique) chart maps the tasks, dependencies, and timeline of a project so you can see exactly what needs to happen and in what order. Each node represents a task with optimistic, most-likely, and pessimistic time estimates, and arrows show which tasks must finish before others can start. PERT charts are essential for identifying the critical path — the longest sequence of dependent tasks that determines your earliest possible finish date. Use one whenever your project has multiple parallel workstreams and you need to spot scheduling bottlenecks before they happen.
Key Features
Critical Path Highlighting
Automatically calculates and color-codes the critical path so you instantly see which tasks have zero slack and must stay on schedule.
Three-Point Time Estimates
Enter optimistic, most-likely, and pessimistic durations per task; the chart computes the weighted expected time using the PERT formula.
Dependency Arrows
Draw task dependencies with directional arrows so predecessors and successors are visually clear at a glance.
Early and Late Start / Finish Times
Toggle on early and late start/finish values per node to expose float and identify scheduling flexibility across your project.
Slack / Float Display
See how much buffer each non-critical task has before it delays the project, helping you reallocate resources confidently.
Flexible Time Units
Switch between hours, days, and weeks to match your project scale without rebuilding the chart from scratch.
Best For
When to Use
- When tasks have dependencies and cannot all start at once
- When task durations are uncertain and you need probabilistic estimates
- When you need to identify which tasks will delay the entire project if they slip
- When multiple teams are working in parallel and you need to coordinate hand-offs
- When a Gantt chart does not clearly show task dependencies and logical flow
- When presenting a project plan to stakeholders who need to see sequencing logic
Common Mistakes
- !Setting identical optimistic and pessimistic estimates, which defeats the purpose of three-point estimation
- !Forgetting to link all tasks to a single start and end node, leaving orphaned tasks with no path
- !Overcrowding the chart with too many micro-tasks — group low-level work into meaningful milestones instead
- !Ignoring float on non-critical tasks and treating every task as urgent, causing unnecessary team stress
- !Using calendar dates instead of durations, which makes the chart invalid when the project start date shifts
- !Confusing PERT with a Gantt chart — PERT shows dependency logic, not a calendar timeline