How to Create a Timeline and Milestone Chart in Excel

Step-by-step

A milestone chart plots key dates on a timeline, so you can see both the milestones and the gaps between them. It’s ideal for planning a project or reporting check-ins and deliverables.

1. Set up the data and three helper columns

The example has dates in B3:B10 and activities in C3:C10. Add three helper columns:

• Date (E3): =IF(B3<>"",B3,"") shows the date only if there is one.
• Activity (F3): =IF(AND(C3<>"",E3<>""),C3,"") shows the activity only if it has both a date and a name.
• Text placement (G3): =IF(F3<>"",10,"") sets how high the label sits. Any number works.

Copy all three down to row 10.

2. Insert an empty line chart

Click an empty cell and go to Insert > Line with Markers. You’ll get a blank chart area.

3. Add the timeline series

Go to Chart Design > Select Data > Add. Name the series Date and select F3:F10 as its values. Excel draws a flat line along zero. Then click Edit under Horizontal (Category) Axis Labels and select the dates in column E, so the axis shows dates.

4. Add the activity series

Add a second series named Activity with G3:G10 as its values, then click OK.

5. Turn the activity series into columns

Right-click one of the activity points, choose Change Series Chart Type, and in Combo set the Activity series to Stacked Column. Then right-click the columns, choose Format Data Series and put them on the Secondary Axis. Delete the new vertical axis on the right.

6. Label the columns with activity names

Go to Select Data, select the Activity series and edit its horizontal axis labels to F3:F10. Then right-click a column, choose Add Data Labels, and in Format Data Labels tick Category Name only, with the label position set to Inside End.

7. Replace the columns with thin lines

Select the columns and go to Add Chart Element > Error Bars > More Error Bar Options. Choose Minus, No Cap and a Percentage of 100%. Then give the columns No fill and No border, so only the error-bar lines remain, connecting each label to the timeline.

8. Style the timeline

Click the horizontal line, choose Format Data Series and set the line to No line. Under Marker, choose a built-in diamond, size 10, in green. Finish with a title, axis font changes, or label tweaks as you like.