Gantt Chart

A Gantt chart is a horizontal bar chart of a project schedule — each task a bar positioned by its start and end date — that makes timelines, overlaps and dependencies instantly readable.

A Gantt chart plots project activities down the vertical axis and time along the horizontal axis, drawing each activity as a bar whose position and length show when it starts, how long it lasts, and when it finishes. Modern Gantt charts add dependency arrows between tasks, milestone diamonds, percent-complete shading, resource assignments and a baseline overlay. Named after Henry Gantt, who popularised it in the 1910s, it remains the default way to visualise and communicate a schedule.

Why it matters

A schedule buried in a spreadsheet is hard to reason about; a Gantt chart shows the shape of the project at a glance — what runs in parallel, what waits on what, where the crunch is. It is equally a planning tool (sequencing and spotting conflicts) and a communication tool (a single picture a sponsor or client understands without training). Dependencies and the critical path become visible rather than implied.

When to use it

Use a Gantt chart for time-bound projects with defined tasks and dependencies — most predictive and hybrid projects. It is less suited to highly fluid Agile work, where boards and burndown charts fit better, though many teams keep a lightweight Gantt at the release or roadmap level.

How to use it

1. Derive activities from your WBS and estimate each one’s duration.
2. Set dependencies (finish-to-start is the most common) so tasks line up correctly.
3. Assign start and end dates, respecting the project calendar and holidays.
4. Add milestones for key checkpoints and assign owners/resources to bars.
5. Baseline the schedule, then update percent-complete regularly to track against it.

Example

For an office move, the Gantt shows "Sign lease" (week 1), "Fit-out" (weeks 2–6, dependent on the lease), "IT setup" (weeks 5–7, overlapping fit-out), and a "Move day" milestone in week 8. The overlap between fit-out and IT is obvious, and the dependency arrow from the lease makes clear that a leasing delay pushes everything.

Template

A Gantt template provides a task list with start/end dates, durations, dependencies, owners and a bar chart that renders automatically — available as Excel/Sheets and in every PM tool.

Browse templates →

Tools

Related topics

FAQs

Alternatives

• Kanban board — for flow-based, continuous work
• Milestone/roadmap chart — a higher-level, less detailed timeline
• Calendar view — for date-driven, low-dependency work