6 steps to building a Gantt chart and managing your tasks without missing a milestone

Published: August 1, 2025

The Gantt chart is the essential project planning tool for any project manager, because it's so helpful.

But how do you construct it? Which tool should you use? Our good old Excel, or dedicated software? 🤔

Don't panic, we've got all the keys to help you create the diagram. To help you find your way around your tasks and deadlines, and meet your deadlines, we'll guide you through 7 steps to build your Gantt chart and lead your project to success, with a free template as a bonus!

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What is a Gantt chart? Definition

A Gantt chart is a project management tool that graphically displays :

the various tasks (ordinate),
and their completion times (on the x-axis) according to the chosen unit of time: days, weeks, months, etc.

Result: each item is materialized by a horizontal bar.

💡 Invented in the 1890s by the Polish engineer Karol Adamiecki, today we use the version created a few years later by the American Henry Gantt below. 👇

What is the purpose of a Gantt chart?

For the project manager, it provides an at-a-glance overview of :

the various tasks involved,
the start, end and estimated duration of each task,
any overlapping tasks,
dependencies between tasks,
the beginning and end of the entire project,
any risks to be avoided when scheduling tasks.

In short, it provides an overall view of the project, enabling the roadmap to be defined, and helping the project manager to plan and manage the project in the best possible conditions.

How to make a Gantt chart in 7 steps?

Step 1: Define the project scope

In the pre-project phase, before getting started, you need to be clear about :

your project objectives,
the timetable: to start with, ask yourself if you have a target delivery date,
available resources, in particular the project team,
expected deliverables, which help define project milestones.

Step 2: List tasks and milestones

Start by breaking down your project into main tasks: these are the major stages of your project.
Identify the main milestones that punctuate the project's progress: deliverables, validation, etc.
For each main task, list the sub-tasks to be carried out.

Milestones represent key stages in the project, such as intermediate objectives to be reached. They segment your project into major phases, punctuated by important events, and serve as benchmarks during steering.

💡 What level of granularity should you choose for subtasking? Depending on the scope of your project, only you can define this.

Our advice: be precise enough to divide the tasks as best you can within the team, and to see the project move forward by completing tasks, but not too much, at the risk of getting lost in the sheer quantity of tasks.

Step 3: Estimate task duration

For some tasks, you already have a defined deadline, if it corresponds to the delivery of a deliverable, for example. So you know what duration to associate with them.
For other tasks, estimate their duration according to the unit you feel is most accurate for your project (hours, days, weeks, months).

👉 How do you estimate the duration of a task? Rely, for example, on :

the difficulty of the task,
the need for coordination and communication: exchanges between stakeholders can slow down task completion,
the validation stages: for example, don't expect your management to be able to validate a decision as soon as it's made, as this may take time depending on their own agendas.

Tasks should then be listed in chronological order, with :

their start date,
end date
and duration.

Each task is shown in the form of a horizontal rectangle, like a progress bar.

Step 4: Create interdependencies

Establish connections between the tasks in your project to define their logical sequence. For example, the completion of the task "Gather user requirements" will determine the start of the next task, "Write the user story".

There are several types of dependency:

start to start: a task can only start if the previous task has started;
start to finish: a task can only finish if the previous task has started;
end to start: a task can only start if the previous one has finished;
end to end: tasks must end at the same time.

💡 Help yourself to a PERT (Program Evaluation and Review Technique) diagram. It "prepares" the Gantt chart by determining an earliest and latest date for each stage. It also highlights the critical path: the optimum sequence of tasks to complete your project by the due date.

Step 5: Plan the tasks

For each task, you already have a start date, an end date and/or a duration. All you have to do is place them on your project schedule.

Several tasks overlap and you don't know how to prioritize them? Use an Eisenhower matrix to define the urgency and importance of each task.

Step 6: allocate human resources

Last step: assign each task to a person in charge. Estimate the amount of work allocated to each person to balance tasks according to their availability. This way, each member of the project team has his or her own schedule and knows how to prioritize tasks.

Our dedicated article shares tips for good project resource management.

Step 7: Monitor and adjust the Gantt as the project progresses

Monitor task progress regularly. Compare the progress bars with the scheduled start dates. Are you behind schedule? A broken dependency? Act quickly to avoid a domino effect.

Adapt your graph as soon as an activity changes duration, a resource becomes unavailable or a new milestone appears.

You can also add a "% progress" column or use a project management tool that automatically updates the data. It's more visual, simpler, and saves your team a lot of time.

Make a Gantt chart in Excel: our free template!

Excel is a great tool for creating a simple Gantt chart for a small-scale project, using a stacked bar chart. It's far more practical than Word or PowerPoint!

Don't bother building it yourself, Appvizer has created a free, ready-to-use Excel Gantt template:

All you have to do is enter your tasks and their deadlines! Please note, however, that Excel is not a collaborative tool, that maintenance can be cumbersome (at the slightest deadline change, the file has to be updated for all stakeholders), and its readability diminishes as the project grows.

Which Gantt chart software should I use?

Free Gantt chart software

To boost performance and agility, opt for free online Gantt chart software:

Elegantt, an extension of Trello,
Teamgantt,
Ganttpro.

However, there are a few drawbacks: the free packages don't offer unlimited history or synchronization with your calendar. The latter two tools are limited in the number of users they can support.

Our selection of project management tools for Gantt mastery

Gantt chart software is a dime a dozen. From simple task management to project portfolio management: all options are available, so it's up to you to find the one that's right for you!

⚒️ Here's our selection of project management software:

Beesbusy is simple to set up and use, offering its users "When", "Who" and "What" views to aid decision-making.
In Fitnet Manager, the manager can visualize and assess all employee schedules at a glance, based on project progress.
monday.com focuses on collaboration, centralizing all project information in a clear, fun interface, with a customizable Gantt view.
In Planzone, task dependencies are updated in real time as the project evolves, highlighting the task flowchart.
Proggio offers a dynamic, easy-to-use and visual solution, covering the company's needs from planning to execution.
Sciforma is particularly well suited to the requirements of agile or Prince2 methods, which emphasize the use of Gantt charts for project management.

Some tools go even further, with customized functionalities to integrate not only Gantt charts, but also other methodologies or tools (mindmap or Kanban, for example). They are ideal for managing very large projects and integrating with other tools.

⚒️

SuitePro G by IQar,
Wrike,
z0 Gravity.

3 examples of how to use a Gantt chart

A Gantt chart is not limited to large companies or engineers. It's a powerful ally in any field where project management is key. Here are a few examples to inspire you 👇.

Example 1: Marketing project

Imagine a product launch campaign. You need to coordinate the writing of content, the filming of a video, and the posting on the website and social networks. Each task has a :

duration,
a start date,
a dependency,
a dedicated team.

The Gantt becomes your control center 🧭.

Example 2: Events

To organize a trade show or conference, you need to plan everything:

room reservation,
communication,
logistics,
speaker scheduling...

Thanks to the graph, you can visualize every step, every milestone, and keep your timing under control, day after day.

Example 3: Construction

In the construction industry, it's impossible to juggle without a good planning tool. Here, the Gantt chart becomes the glue that holds the project together:

coordination of trades,
compliance with standards,
delivery of materials...

In this way, you avoid delays and overlaps between work groups.

🧠 It doesn't matter what sector you're in: as soon as several activities need to be linked up in time, the Gantt is your best ally.

Our latest tips for using the Gantt chart

5 best practices

Here are a few tips on how to get the most out of your Gantt chart:

use a simple, legible color code: green for completed tasks, blue for those in progress, gray for those to come, for example;
indicate the version of the schedule: "version of 28/07" or "last updated on..." to avoid duplication;
show milestones (often represented by diamonds) even if they have no duration;
add a "Status" column: "not started", "in progress", "completed", "to be reviewed", ... ;
adapt the chart to your working environment: departments, teams, priorities... every project is unique.

Mistakes to avoid

Nobody wants a Gantt that looks like a contemporary work of art. Here's what to avoid:

don't overload your diagram: too many elements kill legibility, so stay focused on key tasks;
don't overuse fixed dependencies: your planning must be able to evolve with the work ;
don't ignore downtime: validation, delivery, or just a day's break;
avoid tools that are too rigid: if you spend more time managing your Gantt than moving your project forward, there's a problem;
Don't let your Gantt go to waste.