One way (array-entered: CTRL-SHIFT-ENTER or CMD-RETURN):

=SUM(LEN(A1:A17),-LEN(SUBSTITUTE(A1:A17,"a","")))


In article ,
kas wrote:

I have a list of first names, such as Adam, Mary, Julie, etc in column A and
I want to find out how many of a specific letter is in each cell. I have put
in =COUNTIF(A1:A17,"*a*") and it returns all the letters except doubles in
the name like in Adam it only counts one. I need to count all of the letter
'a'. Please help.