Need help with dynamic range forumla

[MDB123]

I've created a report in excel. The intent is to paste the data into the data tab and refresh the workbook to populate all tabs.

I have additional columns that contain formulas that populate based on the data entered. Each extract will have a different number of rows, so I would like these columns to only populate based on the number of rows in the data entered. Is there a way to do this and avoid having to drag down formulas or delete extra formulas? Like a form of dynamic range?

Example:
Lets say my extract has 10 rows of data. I have column A as open date and column B as closed date.
If I wanted to have column C automatically populate when the data is entered with turnaround time (closed date - open date), how could I do that only going 10 rows down?

Lets says the next weeks data extract has 20 rows...could I have column c populate all 20 rows this time without having to drag the formulas 10 more rows down?

Thanks for any help.

 

[oldbrewer]

=if(a1="","",b1-a1)

in col C copy down say 500 rows

 

[MDB123]

Thanks for the response.

That is basically what I have but my original example is just one of several additional columns, so I would like to do this without having all of the extra formulas.

Would there be any workaround?

 

[oldbrewer]

not clear what you want so give us 10 rows ans 10 columns with pretend data