Tableau row level calculations to compare previous row value and current row value If current row value is greater than previous row value then calculate: Current row value - previous row value = IF INDEX() == 1 THEN ATTR( [Delay Minutes] ) ELSEIF ATTR( [Delay Minutes] ) > LOOKUP(ATTR( [Delay Minutes] ), -1) THEN ATTR( [Delay Minutes] ) - LOOKUP(ATTR( [Delay Minutes] ), -1) ELSE 0 END