These are some of excel formulas I use often.

1. The following to to find the unique case sensitive entries in a column:


2. Formula to count frequencey in excel given two columns, the first comprising of data and the other comprising of the values whose frequency is to be counted:

3. Formula to highlight unequal cells in two columns for excel sheet

Same thing can done in LibreOffice using this:

4. Case Sensitive Duplicate Highlighting in a Column:
In Conditional Formatting, use the following Formula:

5. Formula to highlight entries repeated in another column (column B):


6. Count word in an excel cell or cell range
=IF(LEN(TRIM(E2))=0,0,LEN(TRIM(E2))-LEN(SUBSTITUTE(E2," ",""))+1)

7. Count length of a specific character (e.g. '|')  in a Cell

8. Compare two columns, another better formula:

9. Sum formula:
=SUMIF(B2:B5, "John", C2:C5)
the formula =SUMIF(B2:B5, "John", C2:C5) sums only the values in the range C2:C5, where the corresponding cells in the range B2:B5 equal "John."