Planned vs actual Gantt chart: step by step with an example

A planned vs actual Gantt chart draws two bars for every task. One is the baseline, frozen on the day the plan was agreed. The other shows the dates the work started and finished. To compare them, save the baseline before work begins and record actual dates as tasks close. Then measure the gap at each finish and check which gap moved the project end.

What is the difference between planned and actual dates in a Gantt chart?

Planned dates are a promise and actual dates are a record. A live Gantt chart recalculates whenever something changes, so it only ever shows the current forecast. Once a task slips, the original promise disappears from view unless someone saved it separately. That saved copy is called the baseline.

The GAO Schedule Assessment Guide treats a baseline schedule, and tracking progress against it, as part of good scheduling practice. Without a baseline you can say when the project will finish. You cannot say how far it has drifted from what was promised.

How do you compare planned and actual dates in a Gantt chart in 6 steps?

1. Finish the plan first. Give every task a duration, a person and the tasks it waits for, so the dates mean something.
2. Freeze the baseline. Save a copy of every start and finish on the day the plan is agreed, before any work begins.
3. Record actual dates as you go. When a task really starts or finishes, write that date down instead of overwriting the planned one.
4. Draw both bars. Show the baseline as a thin or pale bar and the actual or forecast dates as a solid bar on the same row.
5. Measure the finish variance. For each task, count the working days between the baseline finish and the actual or forecast finish.
6. Trace which slip moved the end. Follow the waiting arrows from the last task backwards to find the delay that pushed the project finish.

What does a planned vs actual comparison look like in a worked example?

The table below is an example: a small website launch, used here as the baseline. The calendar is Monday to Friday with 6 hours of task work a day, so «1 day» means 6 hours of work. Each person does one task at a time. Work starts on Monday 9 November 2026 and the plan finishes on Thursday 19 November 2026.

Build the site waits for both the copy and the design. Design the pages finishes a day after the copy, so the design is what sets the build start. The copy has a day of room before it would push anything. The domain and email task has even more room: it only has to be done before Publish and check begins.

Now imagine three different things go wrong once work starts. The baseline stays the same in each case. Only the actual dates move.

The lesson of the example is that variance on a task and variance on the project are different numbers. A planned vs actual chart is only useful if you read both.

Which tasks should you watch first when actual dates drift from the plan?

Watch the tasks with no room first. These are the tasks whose finish feeds straight into the next task without any gap, all the way to the last task. A one-day slip there becomes a one-day slip on the project. A slip on a task with room is absorbed until the room runs out.

To find those tasks systematically, follow the method in the critical path guide. Then compare their baseline and actual finishes before anything else.

Which tools keep a baseline for a planned vs actual Gantt chart?

This comparison is as of 2 November 2026 and is based on the pages linked in each row.

tokidu, the project manager by Sinergia Barcelona, is the product of the team that writes this article. In the Free plan, «Dates that work themselves out» calculates when each task should finish. The «Gantt» shows those forecast dates with arrows for what waits for what. «Why that date?» says what pushes a date: the task it waits for, what that person has first, or which days they do not work. The «Plan snapshot» saves what was promised and later shows how much each date has moved, but it belongs to the Max plan, which is not on sale yet. Project desktop and Planner do better here: they keep baselines you can use today, and Project keeps several of them. The Gantt and dates features are listed on the home page.

When should you re-baseline a planned vs actual Gantt chart?

Re-baseline only when the agreement itself changes. That could be new scope, a new deadline accepted by the client, or a task added or removed by decision. Do not re-baseline just because the project is late. Doing so erases the evidence of the delay and makes every later comparison meaningless.

If your tool can store more than one baseline, keep the old one and save the new one alongside it. If it stores only one, export or note the old dates before overwriting them. If you are still building your first chart, start with making a free online Gantt chart and freeze the baseline once everyone agrees on it. More guides like this are collected under Gantt and critical path articles.