How does Project Server calculate the Task Progress displayed in the Project Center Gannt chart?

Question

How does Project Server calculate the Task Progress displayed in the Project Center Gannt chart?

Martin Sullivan 0

Users expect the %Complete value to match the Progress Indicator. Looking to clarify why they do not match.

John Project 49,695 Reputation points Volunteer Moderator

2025-11-14T16:32:07.8866667+00:00

Martin Sullivan,

Just to clarify, are you referring to the Gantt bar progress line for a summary line? For example, in this screen shot, the summary line percent complete is calculated as 18% yet the summary line progress bar shows 33% (i.e. 3 days out of 10).

If this is indeed what you are asking then I'll explain why the difference in an answer. If this is not what you are asking, then please clarify, perhaps with a screen shot.
Martin Sullivan 0 Reputation points

2025-11-14T17:10:57.45+00:00

Yes. But not in Project but rather Project Online though the answer may be the same. See attached. Screenshot 2025-11-14 120742.png Screenshot 2025-11-14 120632.png
John Project 49,695 Reputation points Volunteer Moderator

2025-11-14T19:21:46.5233333+00:00

Martin Sullivan,

Unfortunately I can't relate directly to Project Online or Project Server as I don't user either of those. And it isn't real clear from your screen shots what you are trying to show as the definition for Gantt bars is lacking the bar "from" and "to" criteria. This is how progress is typically defined in Project desktop. Note the "Complete Through" as the progress bar end point.

Summary % Complete = (sum of Actual durations of all subtasks)/(sum of durations of all subtasks) X 100%.

The Complete Through value is calculated as the mean of subtask actual durations added to the summary line start date.

Whether this relates to the Project Online or Project Server environments, I simply do not know but my guess it is very probable those environments calculate progress the same as Project desktop.

If you feel this explanation answers your question, I can't upgrade it to an answer and you can mark it as accepted.

1 answer

Your answer

John Project 49,695 Reputation points Volunteer Moderator

2025-11-14T16:32:07.8866667+00:00

Martin Sullivan,

Just to clarify, are you referring to the Gantt bar progress line for a summary line? For example, in this screen shot, the summary line percent complete is calculated as 18% yet the summary line progress bar shows 33% (i.e. 3 days out of 10).

If this is indeed what you are asking then I'll explain why the difference in an answer. If this is not what you are asking, then please clarify, perhaps with a screen shot.
Martin Sullivan 0 Reputation points

2025-11-14T17:10:57.45+00:00

Yes. But not in Project but rather Project Online though the answer may be the same. See attached. Screenshot 2025-11-14 120742.png Screenshot 2025-11-14 120632.png
John Project 49,695 Reputation points Volunteer Moderator

2025-11-14T19:21:46.5233333+00:00

Martin Sullivan,

Unfortunately I can't relate directly to Project Online or Project Server as I don't user either of those. And it isn't real clear from your screen shots what you are trying to show as the definition for Gantt bars is lacking the bar "from" and "to" criteria. This is how progress is typically defined in Project desktop. Note the "Complete Through" as the progress bar end point.

Summary % Complete = (sum of Actual durations of all subtasks)/(sum of durations of all subtasks) X 100%.

The Complete Through value is calculated as the mean of subtask actual durations added to the summary line start date.

Whether this relates to the Project Online or Project Server environments, I simply do not know but my guess it is very probable those environments calculate progress the same as Project desktop.

If you feel this explanation answers your question, I can't upgrade it to an answer and you can mark it as accepted.

Answer 1

Hello @Martin Sullivan,

Good day! Thank you for posting your valuable question on Microsoft Q&A forum.

To help us provide the most accurate guidance, could you share a few additional details?

Which version of Microsoft Project are you using? (Go to File > Account and check under About Project.)
Could you provide a screenshot (with your personal information removed) showing:
- All the columns you’ve added to your Project view
- The % Complete column alongside the Progress Indicator
When you said they do not match, did you mean that when you changed values like Duration or Actual Duration, the % Complete update while the Progress Indicator remains unchanged?

This extra context will help us better understand your setup and the steps you’ve already taken, so we can tailor our solution specifically to your environment.

I apologize for not jumping straight to a solution. I want to avoid suggesting anything that might be inaccurate or unhelpful. Once I have the details above, I’ll be able to assist you more effectively and guide you toward the right resolution.

Looking forward to your response so we can get this sorted out for you as soon as possible.

If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Tamara-Hu 8,315 Reputation points Microsoft External Staff Moderator

2025-11-15T11:49:31.16+00:00

Hello @Martin Sullivan,

I hope you're having a nice day! I wanted to follow up to see if you need any additional help. I hope everything is going well on your part.

I can see you've already received help from another moderator. If you have any doubts, need clarification, or new questions have arisen, don't hesitate to get in touch. I am here to support you and happy to help.

Your satisfaction is important to me, and I want to make sure you feel safe and supported throughout the process. Just tell me how I can help you more.

I look forward to hearing from you!

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How does Project Server calculate the Task Progress displayed in the Project Center Gannt chart?

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