=SMALL(IF(data=1,ROW(INDIRECT("1:"&ROWS(data)))),R OWS($1:1))

ctrl+shift+enter, not just enter
copy down


"Mitch Powell" wrote:

I have a column in which rows will contain the value of "1" when that row
meets a certain criteria. I want to build an ascending list in another
location of the row numbers in that column that contain "1". Any ideas?