Assuming there are no empty cells in the date range (empty cells will
evaluate as month January).

=SUMPRODUCT(--(MONTH(A1:A20)=1),--(M1:M20="res"))/SUMPRODUCT(--(MONTH(A1:A20)=1),--(M1:M20<""))

Format as PERCENTAGE

--
Biff
Microsoft Excel MVP


"Art-SNL" wrote in message
...
I have a spreadsheet with dates in Column A, and either the word "Res" or
"Comm" in Column M. How can I find out the percentage of "Res" for all
the
records in January?

PS - there is an abundance of extreme talent in this community! Thanks
for
all your postings!