Try the array formula

=SUM(IF(A1:A10<"",IF(ISNA(MATCH(A1:A10,B1:B20,0)) ,1,0)))

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Jacob Skaria


"Faraz A. Qureshi" wrote:

I want to check how many of the entries in A1:A10, are not found to be
existing in another list, suppose B1:B20.

Tried out:

=SUMPRODUCT(--(ISNA(VLOOKUP(A1:A10,B1:B20,1,0))))

but failed. What might be the reason? and what might be its solution except
then a helper column?

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Best Regards,

Faraz