Grouping duplicates

[undemane]

I have an excel sheet with several columns. In column B, I have Project ID # with several rows of activities for each Project ID #.

I want to display (on another sheet), how many unique Project ID #s I have. How do I do that? Thank you.

 

[venkat1926]

advance filter columnb B (with column headings) and tick the unique records only (copy in anohter location),criteria range will be blank.
you will get uniuqe IDs and use countA to get the number of unique values.

see help under "advanced filter"