I have tried both of these in Google Spreadsheets and continue to get circular dependency errors. I am trying to show blank when the result is 0. New values are entered daily and want to have the average formula run down the entire column so I don't have to drag the previous day's box down to copy the info.
=IF(C19="","",sum(C14:C18))
=IF(C19="0","",sum(C14:C18))