How to Create a Project Timeline: 7 Steps and an Example

Here is how to create a project timeline: write down the scope and the finish line, break the work into tasks, estimate each task in working days, put the tasks in order, then turn those durations into dates and mark your milestones. Finally, add a buffer of working days in front of any date you cannot move, such as a launch or an event.

Below are the seven steps, the formulas that turn durations into dates in Google Sheets and Excel, and a complete example timeline for a small business website.

Project Timeline Steps

1. Define the scope and the finish line. Write one paragraph: what you will deliver, for whom, what “done” looks like and what is out of scope. For our example: a six-page website with a contact form, launched by late July, with no online shop.
2. Break the work into tasks. Split each deliverable into tasks between one and ten working days long. Anything longer hides problems until it is too late to fix them. Our work breakdown structure example shows how to get from deliverables to tasks.
3. Choose your milestones. Pick three to five moments where work is approved or handed over.
4. Estimate durations in working days. Count the days a task really takes, including waiting for feedback. Give client reviews their own task with their own days, because feedback rarely arrives the same afternoon.
5. Put the tasks in order. For each task, ask what must be finished before it can start. Most tasks wait on one other task, and some can run side by side.
6. Turn durations into dates. Start from the kickoff date and let a formula count forward, skipping weekends and holidays (formulas below).
7. Add buffers and share the plan. Put a buffer before each fixed date, send the timeline to everyone who owns a task, and review it once a week.

How to Choose Project Milestones

A useful milestone passes three tests. It is a decision or a handover, not just a date. It usually involves someone outside the day-to-day work, such as a client or a manager. And you can answer it with yes or no: “design approved” is either true or not, while “design mostly done” is not a milestone.

For most small projects, milestones fall at the end of each phase: scope approved, design approved, content in place, launch. If a phase runs longer than about three weeks, add one in the middle so a slip shows up early.

Formulas That Turn Durations Into Dates

Set up a table with Phase in A, Task in B, Days (working days) in C, Starts after in D, Start in E and End in F, and list holidays on a sheet named Holidays in A2:A12. The formulas are identical in Google Sheets and Excel:

• First start (E2): type the kickoff date, for example 6/7/2027.
• End (F2): =WORKDAY(E2, C2-1, Holidays!$A$2:$A$12)
• Next start (E3): =WORKDAY(F2, 1, Holidays!$A$2:$A$12)

The -1 in the end formula matters: a one-day task starts and ends on the same day, so a task of C2 days ends C2 minus 1 working days after it starts. The start formula moves one working day past the end of the task it waits on. For a task that runs in parallel, point its start at the end of the task it really depends on, not the row above.

Chain every task this way and the timeline becomes live: change one duration and every later date moves. Our NETWORKDAYS guide explains WORKDAY in more detail, including custom weekends and counting working days between two dates.

Project Timeline Example: Small Website Launch

A designer and a copywriter are building a six-page site for a local business, with the owner reviewing. Kickoff is Monday, June 7, 2027. The holiday list has two dates: Friday, June 18 (Juneteenth, observed) and Monday, July 5 (Independence Day, observed).

Phase	Task	Days	Starts after	Start	End
Plan	Kickoff call and scope sign-off	1	None	Mon Jun 7	Mon Jun 7
Plan	Sitemap and content plan	3	Kickoff	Tue Jun 8	Thu Jun 10
Milestone	Scope approved				Thu Jun 10
Design	Wireframes	3	Sitemap	Fri Jun 11	Tue Jun 15
Design	Visual design	5	Wireframes	Wed Jun 16	Wed Jun 23
Content	Write page copy	8	Sitemap	Fri Jun 11	Wed Jun 23
Design	Owner review and revisions	3	Visual design	Thu Jun 24	Mon Jun 28
Milestone	Design approved				Mon Jun 28
Build	Build pages	8	Design approved	Tue Jun 29	Fri Jul 9
Build	Add copy and images	3	Build pages	Mon Jul 12	Wed Jul 14
Milestone	Content in place				Wed Jul 14
Launch	Test on phones, browsers and forms	3	Add copy	Thu Jul 15	Mon Jul 19
Launch	Owner review and fixes	2	Testing	Tue Jul 20	Wed Jul 21
Launch	Buffer	3	Fixes	Thu Jul 22	Mon Jul 26
Milestone	Launch				Tue Jul 27

Reading the Example

The project spans 51 calendar days but only 35 working days, counting kickoff and launch day. Both holidays change dates: visual design needs 5 working days but runs Wednesday to the following Wednesday because of June 18, and building the pages ends on Friday, July 9 instead of Thursday because of July 5.

Copywriting runs side by side with design. It finishes on June 23 but is not needed until “Add copy and images” starts on July 12, which leaves 11 working days of slack. That is deliberate: copy is often the task that runs late, especially when the business owner writes or approves it, and here it can slip more than two weeks without moving the launch.

Everything else sits on one straight line: 31 working days of tasks where each waits for the one before. Any slip there pushes the launch, which is what the buffer is for.

The launch lands on a Tuesday on purpose. If something breaks, the whole team is around for the rest of the week, which is not true of a Friday launch.

Working-Day Buffers: How Much and Where

Put the buffer as one visible block in front of each fixed date, not as a little extra hidden inside every task. Padding spread across tasks tends to get used up quietly, while a named buffer row shows exactly how much slack is left.

A simple rule we use: about 10% of the working days on the straight-line chain, rounded to the nearest whole day, and more when outside reviewers or unfamiliar work are involved. The example has 3 buffer days on 31 working days of chained tasks.

When the deadline is fixed, schedule backward with a negative number of days. To keep three buffer days before a July 27 launch, fixes must finish by:

=WORKDAY(DATE(2027,7,27), -4, Holidays!$A$2:$A$12)

That returns Wednesday, July 21: four working days back covers the three buffer days and lands on the last day of fixes. Work back the same way, task by task, and you get the latest possible start for each one. If the latest start for kickoff is already in the past, cut scope or move the deadline now, not in week five. Our event planning timeline applies this backward method to a 12-week event plan.

Then watch the buffer week by week. If testing slips by two days, the buffer shrinks to one day and launch still holds. If it slips by four, launch moves, and you know it a week ahead instead of on the morning itself.

Turn the Timeline Into a Gantt Chart

A table of dates is the timeline, but bars make overlaps and slack visible at a glance: you would see the copy bar ending long before the build bar needs it. To draw the bars yourself, follow how to make a Gantt chart in Google Sheets or the Excel version. Both read the same Start and End columns you built above.

If you would rather enter tasks once and get the chart, phases, holidays and a today marker without building formulas, use our Gantt chart template.

Before you share the timeline, walk through it with each task owner and ask one question per task: “Can you really finish this in that many working days, given what else you have on?” Adjust the durations now, while every change is still free.