Tr this

=SUM(INDEX(A1:A1000,LARGE(ROW(A1:A1000)*(A1:A1000< 0),13)):A1000)

This an array which must be entered using CTRL+Shift+Enter and not just enter.
If you do it correctly then Excel will put curly brackets around the formula
{}. You can't type these yourself..

Mike

"vdubluv74" wrote:

I am looking for a formula that calculates the last 13 numbers in a column
that are greater than 0. thanks