I didn't realise Hui, but the formule [ =+TREND(OFFSET($J$6,+MATCH($C7,$J$7:$J$16,1),+MATCH($D7,OFFSET($K$6:$P$6,MATCH($C7,$J$7:$J$16,1)-1,0)),1,2),OFFSET($J$6,+MATCH($C7,$J$7:$J$16,1)-1,+MATCH($D7,OFFSET($K$6:$P$6,MATCH($C7,$J$7:$J$16,1)-1,0)),1,2),$D7) ] doesn't provide an exact match...