# What Is a Gantt Chart? Definition, Example and How to Build One

> A Gantt chart is a bar chart of a project schedule: tasks down the side, time across the top. See an example, the six build steps and the mistakes to avoid.

_Source: https://professionalstoolkit.com/articles/what-is-a-gantt-chart — The Professional's Toolkit · updated October 2026_

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A **Gantt chart** is a bar chart of a project schedule: tasks run down the left side, time runs across the top, and each task is a bar whose length shows how long it takes.[1] Modern versions add the links between tasks and the milestones that mark key dates. The method in one line: break the work into tasks, estimate each one, link what depends on what, then draw the bars from the start date forward. Done well, a Gantt chart answers the question every project gets asked: *when will this be done, and what is holding it up?*


**4 parts** — Every Gantt chart needs a task list, a timeline, bars and dependencies



- **1896** — Adamiecki's harmonogram, the first known chart of this type
- **1910-1915** — When Henry Gantt designed the chart named after him
- **4 link types** — Finish-to-start is the default link type


## What a Gantt chart shows: bars, links and milestones

Every Gantt chart is built from four parts. The **task list** sits on the vertical axis, usually grouped into phases. The **timeline** runs along the horizontal axis in days, weeks or months. The **bars** start on each task's start date and end on its finish date, so a long bar means a long task. Many charts also shade part of each bar to show percent complete, and draw a vertical line for today, so you can see at a glance what is late. Red flags jump out.

The fourth part is what turns a picture into a plan: **dependencies**. A dependency says one task cannot move until another does. The default type is finish-to-start, where task B cannot begin until task A is complete. Microsoft's own example is simple: you can't pour concrete until the foundation is dug.[2] There are three other types, start-to-start, finish-to-finish and start-to-finish, but most small-team projects never need more than the first one.

Milestones complete the picture. A milestone is a point in time, not a stretch of work. It has no duration and usually shows as a small diamond on its date: contract signed, beta ready, launch day. Milestones are what you report upward. Executives rarely read forty bars, but they will read five diamonds and ask if any of them moved.

## Why the Gantt chart in project management still matters

The chart is old. It is older than most of the tools that draw it. Karol Adamiecki built a version he called a harmonogram in 1896, and Henry Gantt designed the chart that carries his name around 1910 to 1915.[1] The earliest charts were drawn on paper. Any schedule change meant redrawing the whole thing, which is why planners later cut bars from paper strips or blocks they could slide around.

That history explains why the format survived. A Gantt chart can be read without training. A critical path network diagram shows relationships better, but people need to learn how to read it; a row of bars across a calendar needs no explanation. Software kept the familiar picture and removed the redrawing. Today the same task data usually feeds both views, so the chart updates itself when a date moves.

So where does a Gantt chart fit in project management today? It works best for projects with a fixed end date, a clear order of work and several people whose tasks depend on each other. Think of a product launch, an office move, a client onboarding or a construction job. It fits less well when the work is a steady stream of small requests with no real sequence. That kind of work belongs on a board. If your project does fit the format, our guide on [building a Gantt chart in Excel](/articles/how-to-make-a-gantt-chart-in-excel) shows the spreadsheet version, so you can try it before buying anything.


> 💡 **Try the format before buying:** Sketch your first Gantt chart in a spreadsheet for one short project. If you keep retyping dates after every delay, you have found the reason to use a tool.


## How to build a project timeline in six steps

Building a project timeline is mostly thinking, not drawing. The chart is the last step. Follow this order and the bars almost place themselves.

1. **Set the end point.** Write down what *done* means and the date it must happen. Without a fixed goal, the chart has nothing to measure against.
2. **List the work.** Break the project into tasks small enough to estimate, usually a few days to two weeks each. Group them into phases such as plan, build, test and launch.
3. **Estimate durations.** Ask the person doing each task, not the person who wants it finished. Add working days only, and block out holidays.
4. **Link the dependencies.** For each task, ask one question: what must be finished before this can start? Most links will be finish-to-start.
5. **Add milestones.** Put a diamond at each phase end and at every date someone outside the team cares about.
6. **Assign owners and draw.** Give every bar one name. Then set the start date and let the chart lay out the rest.

Once it is drawn, look for the longest chain of linked tasks from start to finish. That chain is the **critical path**. Any delay on it pushes the end date; a delay elsewhere may not. Knowing which tasks sit on the path tells you where to spend attention every week.

## A Gantt chart example: launching a small website

Here is a Gantt chart example for a five-week website launch with four people. The table holds the data a chart is drawn from: each task, its duration, and what it waits for.

| Task | Owner | Duration | Waits for |
|---|---|---|---|
| Write the brief | Project lead | 3 days | (start) |
| Draft site map | Designer | 2 days | Brief |
| Write page copy | Writer | 8 days | Site map |
| Design pages | Designer | 7 days | Site map |
| Build pages | Developer | 8 days | Design |
| Load copy and test | Developer | 3 days | Build, copy |
| Milestone: launch | Project lead | 0 days | Test |

Drawn as bars, the copy and the design run side by side once the site map is done. That overlap is where the chart earns its keep. The writer has more days than the work needs, so a slow week on copy changes nothing. The designer and developer do not. They have no slack. Their tasks form the critical path: brief, site map, design, build, test, launch. If the design slips three days, launch slips three days, and the chart shows it the moment you move the bar.

That is the whole value of the format in one view. A to-do list says what needs doing. A Gantt chart says what happens to the end date when one thing runs late.


> 💡 **Find the critical path first:** Before the weekly check-in, look only at the tasks on the longest linked chain. A slip anywhere else may not move the end date at all.


## Common Gantt chart mistakes to avoid

Most broken charts fail in the same few ways. None of them are about the drawing.

**Typing dates instead of linking tasks.** If every bar has a hand-entered start date, a delay in one task changes nothing else on the chart. The plan looks fine while the real schedule falls apart. Link the tasks and let the dates follow.

**Too much detail.** A chart with three hundred one-hour tasks is unreadable and goes stale in a day. Keep tasks at the size a person reports on once a week. Put the checklists inside the task, not on the chart.

**No owner on a bar.** A task owned by *the team* is owned by nobody. One name per bar, even when several people help.

**Treating the plan as a contract.** A Gantt chart is a forecast. Estimates will be wrong, and the chart should change when they are. Update it on a fixed rhythm, weekly for most teams, and compare the new end date with the old one.

**Ignoring who is overloaded.** Two bars side by side look fine until you notice they belong to the same person. Scan each owner's row before you promise a date.


> ⚠ **Hand-typed dates hide delays:** If bars are not linked, one late task leaves every later bar where it was. The chart looks on time while the real schedule has already slipped.


## When a Gantt chart outgrows a spreadsheet

A spreadsheet can draw a decent Gantt chart for a short project with one planner. It starts to hurt when three things pile up. Dependencies stop moving on their own, so one late task means retyping every date after it. Several people edit the same file and overwrite each other. And status lives in someone's head until they update a cell by hand.

That is the point where a shared project tool earns its place: the task list, the dates and the owners live in one place the whole team updates, instead of in one person's file. Three products we checked put a Gantt or timeline view on top of that task list.


### Teamwork.com — solves this

Teamwork.com includes a Gantt view on its Free Forever plan, next to list, table and Kanban views of the same tasks, and its project templates can carry task lists with dependencies already set.

- Where it stops: Free Forever is capped at 5 users and 5 projects.
- Plan: Free Forever
- More: [Teamwork.com](https://professionalstoolkit.com/tools/teamwork)



### Asana — solves this

Asana lays the same tasks out on a Timeline and Gantt view, so a project you already track as a list becomes a dated schedule without re-entering it.

- Where it stops: The free Personal plan does not include Timeline.
- Plan: Starter
- How Asana does it: [Set up Asana, timeline included](https://professionalstoolkit.com/articles/getting-started-with-asana)
- More: [Asana](https://professionalstoolkit.com/tools/asana)



### Wrike — solves this

Wrike adds interactive Gantt charts to the projects and tasks you already manage in it, so the same work gets a schedule view without a separate file.

- Where it stops: The Free plan has project and task management and a board view, but no Gantt chart.
- Plan: Team
- How Wrike does it: [Set up Wrike and its Gantt](https://professionalstoolkit.com/articles/how-to-get-started-with-wrike)
- More: [Wrike](https://professionalstoolkit.com/tools/wrike)


For a full side-by-side of how seven tools handle timelines, dependencies and milestones, see our guide to [Gantt chart software](/articles/gantt-chart-tools).


## FAQ

**What is the difference between a Gantt chart and a project timeline?**

A project timeline can be any view of work across dates, often just milestones on a line. A Gantt chart is a detailed timeline: every task gets a bar, an owner and links to the tasks it depends on.

**Should I use a Gantt chart or a Kanban board?**

Use a Gantt chart when the work has a fixed end date and a clear order of tasks. Use a Kanban board when the work is a steady flow of independent requests. Many teams plan on a Gantt chart and run daily work on a board.

**Can I make a Gantt chart for free?**

Yes. Excel and Google Sheets can draw one with a stacked bar chart or conditional formatting, and some project tools include a Gantt view on their free plan, for example Teamwork.com's Free Forever plan.

**Is a Gantt chart used in agile projects?**

It can be, at the release level. Agile teams usually run short sprints on a board and keep a Gantt chart, if any, for the few dates others depend on, such as a launch or a contract milestone.


## The bottom line

A Gantt chart is a calendar of your project's work, with each task as a bar and the links between tasks showing what waits for what. Its real value is not the picture. It is the moment a task slips and you can see, right away, whether the end date moves. Build it in the right order: goal, tasks, estimates, dependencies, milestones, owners. Keep tasks at a size people report on weekly, and update the chart on a fixed rhythm. Start in a spreadsheet if the project is small and you plan alone. Move to a tool once several people and linked dates are involved.



## Sources

[1] en.wikipedia.org — https://en.wikipedia.org/wiki/Gantt_chart (Oct 2026)
[2] Microsoft Support — https://support.microsoft.com/en-us/project/link-tasks-in-a-project (Oct 2026)