diff --git a/cart-grain.go b/cart-grain.go
index 9d9fecf..35847e0 100644
--- a/cart-grain.go
+++ b/cart-grain.go
@@ -43,6 +43,8 @@ type CartItem struct {
 	Sku         string      `json:"sku"`
 	Name        string      `json:"name"`
 	Price       int64       `json:"price"`
+	TotalPrice  int64       `json:"totalPrice"`
+	TotalTax    int64       `json:"totalTax"`
 	OrgPrice    int64       `json:"orgPrice"`
 	Stock       StockStatus `json:"stock"`
 	Quantity    int         `json:"qty"`
@@ -249,9 +251,9 @@ func (c *CartGrain) FindItemWithSku(sku string) (*CartItem, bool) {
 	return nil, false
 }
 
-func GetTaxAmount(total int, tax int) int {
+func GetTaxAmount(total int64, tax int) int64 {
 	taxD := 10000 / float64(tax)
-	return int(float64(total) / float64((1 + taxD)))
+	return int64(float64(total) / float64((1 + taxD)))
 }
 
 func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPayload, error) {
@@ -312,7 +314,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 					tax = int(msg.Tax)
 				}
 
-				taxAmount := GetTaxAmount(int(msg.Price), tax)
+				taxAmount := GetTaxAmount(msg.Price, tax)
 
 				c.Items = append(c.Items, &CartItem{
 					Id:          c.lastItemId,
@@ -321,6 +323,8 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 					Sku:         msg.Sku,
 					Name:        msg.Name,
 					Price:       msg.Price,
+					TotalPrice:  msg.Price * int64(msg.Quantity),
+					TotalTax:    int64(taxAmount * int64(msg.Quantity)),
 					Image:       msg.Image,
 					Stock:       StockStatus(msg.Stock),
 					Disclaimer:  msg.Disclaimer,
@@ -333,7 +337,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 					OrgPrice:    msg.OrgPrice,
 					ArticleType: msg.ArticleType,
 					Outlet:      msg.Outlet,
-					Tax:         taxAmount,
+					Tax:         int(taxAmount),
 				})
 				c.UpdateTotals()
 				c.mu.Unlock()
@@ -561,8 +565,12 @@ func (c *CartGrain) UpdateTotals() {
 	c.TotalTax = 0
 	c.TotalDiscount = 0
 	for _, item := range c.Items {
-		c.TotalPrice += item.Price * int64(item.Quantity)
-		c.TotalTax += int64(item.Tax) * int64(item.Quantity)
+		rowTotal := item.Price * int64(item.Quantity)
+		rowTax := int64(item.Tax) * int64(item.Quantity)
+		item.TotalPrice = rowTotal
+		item.TotalTax = rowTax
+		c.TotalPrice += rowTotal
+		c.TotalTax += rowTax
 		itemDiff := max(0, item.OrgPrice-item.Price)
 		c.TotalDiscount += itemDiff * int64(item.Quantity)
 	}