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

Published: 1 August 2025

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

But how do you construct it? Which tool should you use for your activity? 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 different tasks (on the ordinate)
and their completion times (on the horizontal axis) according to the chosen unit of time: days, weeks, months, etc.

Result: each item is materialised by a horizontal bar.

💡 Although it was invented in the 1890s by the Polish engineer Karol Adamiecki, today we use the version produced a few years later by the American Henry Gantt below. 👇

What is the purpose of a Gantt chart?

For the project manager, it allows you to see at a glance :

the different tasks planned
the start, finish and estimated duration of each task,
any overlaps between tasks
any dependencies between tasks,
the start and finish of the entire project,
any risks to be avoided when planning 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 then manage the project in the best possible conditions.

How to make a Gantt chart in 7 steps?

Step 1: Define the scope of the project

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

your project objective (s ),
the timetable: to start with, ask yourself whether you have a planned delivery date,
the resources available, particularly the project team,
the expected deliverables, which help to define the project milestones.

Step 2: Draw up a list of 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 progress of the project: 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 achieved. They segment your project into major phases, punctuated by important events, and serve as reference points when steering.

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

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

Step 3: Estimate the duration of the tasks

For some tasks, you already have a defined deadline, if it corresponds to the delivery of a deliverable, for example. So you know how long they will take.
For the 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? For example, rely on :

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

The tasks should then be broken down in chronological order, with :

their start date
their end date
and their duration.

Each task takes 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 task has finished;
end to end: tasks must end at the same time.

💡 Use 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 deadline.

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 prioritise them? Use an Eisenhower matrix to define the degree of 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 the tasks according to their availability. This way, each member of the project team has their own schedule and knows how to prioritise their tasks.

Our dedicated article shares some tips for good project resource management.

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

Regularly monitor the progress of tasks. Compare the progress bars with the scheduled start dates. Are you behind schedule? A broken dependency? You need to 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 is reached.

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

Making a Gantt chart in Excel: our free template!

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

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

All you have to do is fill in your tasks and their deadlines! Please note, however, that Excel is not a collaborative tool, that its maintenance can be cumbersome (the slightest change to a deadline means that the file has to be updated for all the parties involved), and that 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 do not offer unlimited history or synchronisation with your calendars. The last two tools also have a limited number of users.

Our selection of project management tools to master Gantt

Software for creating a Gantt chart is legion. From simple task management to project portfolio management: there are so many options, it's up to you to find the one that's right for you!

⚒️ Here is our selection of project management software:

Beesbusy is simple to set up and use, offering its users 'When', 'Who' and 'What' views to help them make decisions.
In Fitnet Manager, the manager can view and assess all the staff schedules at a glance, based on the progress of the project.
monday.com focuses on collaboration and centralises all project information in a clear, fun interface, with a customisable Gantt view.
In Planzone, dependencies between tasks are updated in real time as the project progresses, highlighting the task flowchart.
Proggio offers a dynamic, easy-to-use and visual solution that covers the company's needs from planning to execution.
Sciforma is particularly well suited to the requirements of agile and Prince2 methods, which use Gantt charts for project management.

It should be noted that some tools go even further, with tailor-made features to integrate the Gantt chart, 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 centre 🧭.

Example 2: Events

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

room reservation
communication
logistics
speaker schedule...

Thanks to the graph, you can visualise each stage, each 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 cement of the project, enabling you to manage :

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

In this way, you can 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 together over a period of time, the Gantt is your best ally.

Our latest tips for using the Gantt chart

5 best practices

Here are a few things you should do to get the most out of your Gantt chart:

use a simple, legible colour code: green for completed tasks, blue for those in progress, grey for those to come, for example;
indicate the version of the schedule: "version of 28/07" or "last updated on..." to avoid duplication;
show the milestones (often represented by diamonds) even if they have no duration;
add a "Status" column: "not started", "in progress", "completed", "to be reviewed", etc;
adapt the chart to your working environment: departments, teams, priorities, etc. Each 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 the key tasks;
don't overuse fixed dependencies: your schedule 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 making progress on your project, there's a problem;
Don't let your Gantt fall by the wayside.