If you know the last value is a number you can use this formula.

=MATCH(999999999,CI:CI)

I am not exactly sure why it works, but it does.

To use with the countif you would use this formula.

=COUNTIF(INDIRECT("CI6:CI"&MATCH(999999999,CI:CI)) ,"")

"Mitchell" wrote:

I have a sheet that users can add lines. I need to determine the last
row/cell with a value. This is to be used in countif(ci6:(need to put in last
cell),"")

Thanks for the help.