You could also copy all of the information from the column that you want in another sheet and then remove duplicates and then do a countif formula using the unique fields. Which is more work then selecting all of your data and then inserting a pivot table. I am assuming you are using excel and not just Google Sheets otherwise you will have to do the unique thing that homer posted. Excel + Pivot table is the easiest way to do this if you don't have a tool like Alteryx, R, Python or Tableau to do this. There is a way to do this in VBA if you just have excel but that is long and complicated.