diff --git a/internal/modules/closings/dto/closing.dto.go b/internal/modules/closings/dto/closing.dto.go
index 429495b7..c05bd741 100644
--- a/internal/modules/closings/dto/closing.dto.go
+++ b/internal/modules/closings/dto/closing.dto.go
@@ -204,3 +204,20 @@ func ToClosingDetailDTO(e entity.ProjectFlock) ClosingDetailDTO {
 		ClosingListDTO: ToClosingListDTO(e),
 	}
 }
+
+func CalculateAgeFromChickinDataProduksi(projectFlockKandang *entity.ProjectFlockKandang, deliveryDate *time.Time) int {
+	if projectFlockKandang == nil || deliveryDate == nil || len(projectFlockKandang.Chickins) == 0 {
+		return 0
+	}
+
+	earliestChickinDate := projectFlockKandang.Chickins[0].ChickInDate
+	for _, chickin := range projectFlockKandang.Chickins {
+		if chickin.ChickInDate.Before(earliestChickinDate) {
+			earliestChickinDate = chickin.ChickInDate
+		}
+	}
+
+	ageInDays := int(deliveryDate.Sub(earliestChickinDate).Hours() / 24)
+	ageInWeeks := ageInDays / 7
+	return ageInWeeks
+}
diff --git a/internal/modules/closings/services/closing.service.go b/internal/modules/closings/services/closing.service.go
index 895f05f7..10007fd9 100644
--- a/internal/modules/closings/services/closing.service.go
+++ b/internal/modules/closings/services/closing.service.go
@@ -469,8 +469,11 @@ func (s closingService) GetClosingDataProduksi(c *fiber.Ctx, projectFlockID uint
 			return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to fetch FCR standard data")
 		}
 	}
-	// masih dummy, karena tab penjualan agenya masih dummy
-	age := 1.0
+	age, err := s.calculateAverageSalesAge(c.Context(), projectFlockID)
+	if err != nil {
+		s.Log.Errorf("Failed to calculate sales age for project flock %d: %+v", projectFlockID, err)
+		return nil, fiber.NewError(fiber.StatusInternalServerError, "Failed to fetch sales age data")
+	}
 
 	feedUsedPerHead := 0.0
 	if population > 0 {
@@ -599,6 +602,40 @@ func (s closingService) GetClosingDataProduksi(c *fiber.Ctx, projectFlockID uint
 	return &result, nil
 }
 
+func (s closingService) calculateAverageSalesAge(ctx context.Context, projectFlockID uint) (float64, error) {
+	deliveryProducts, err := s.MarketingDeliveryProductRepo.GetDeliveryProductsByProjectFlockID(ctx, projectFlockID, func(db *gorm.DB) *gorm.DB {
+		return db.
+			Preload("MarketingProduct").
+			Preload("MarketingProduct.ProductWarehouse").
+			Preload("MarketingProduct.ProductWarehouse.ProjectFlockKandang").
+			Preload("MarketingProduct.ProductWarehouse.ProjectFlockKandang.Chickins")
+	})
+	if err != nil {
+		return 0, err
+	}
+
+	var (
+		totalQty      float64
+		totalAgeWeeks float64
+	)
+
+	for _, product := range deliveryProducts {
+		if product.Qty == 0 {
+			continue
+		}
+		projectFlockKandang := product.MarketingProduct.ProductWarehouse.ProjectFlockKandang
+		ageWeeks := dto.CalculateAgeFromChickinDataProduksi(projectFlockKandang, product.DeliveryDate)
+		totalAgeWeeks += float64(ageWeeks) * product.Qty
+		totalQty += product.Qty
+	}
+
+	if totalQty == 0 {
+		return 0, nil
+	}
+
+	return totalAgeWeeks / totalQty, nil
+}
+
 func calculatePerformanceMetrics(averageWeight, totalWeight, feedUsed, basePopulation, depletion, age float64, standards []entity.FcrStandard) dto.ClosingPerformanceDTO {
 	mortalityStd, fcrStd := closestFcrValues(standards, averageWeight)
 
@@ -612,8 +649,8 @@ func calculatePerformanceMetrics(averageWeight, totalWeight, feedUsed, basePopul
 		mortalityAct = (depletion / basePopulation) * 100
 	}
 
-	deffMortality := mortalityStd - mortalityAct
-	deffFcr := fcrStd - fcrAct
+	deffMortality := mortalityAct - mortalityStd
+	deffFcr := fcrAct - fcrStd
 
 	awg := 0.0
 	if age > 0 {