Calculating Date Difference in SharePoint using column Condition

Question

I have sharepoint list to track projects:

1. Date Started
2. Date Completion
3. Project Status (On-going, Completed, Hold, Cancelled)

I want to compute the number of days the project was completed.

If isblank[Completion Dated], today()-[date started] else [Date completion]- [Date Started]

How do I write this in the calculated formula?

Answer 1

Use formula like:

=IF(ISBLANK([Date Completion]), Today()-[Date Started], [Date Completion]-[Date Started]) 

Note: Calculated column will be evaluated only when list item is added/updated or calculated column formula is updated.