diff --git a/cart-grain.go b/cart-grain.go
index a8f9be9..082d2a9 100644
--- a/cart-grain.go
+++ b/cart-grain.go
@@ -75,6 +75,8 @@ type CartGrain struct {
 	Id                CartId          `json:"id"`
 	Items             []*CartItem     `json:"items"`
 	TotalPrice        int64           `json:"totalPrice"`
+	TotalTax          int64           `json:"totalTax"`
+	TotalDiscount     int64           `json:"totalDiscount"`
 	Deliveries        []*CartDelivery `json:"deliveries,omitempty"`
 	Processing        bool            `json:"processing"`
 	PaymentInProgress bool            `json:"paymentInProgress"`
@@ -301,7 +303,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 			existingItem, found := c.FindItemWithSku(msg.Sku)
 			if found {
 				existingItem.Quantity += int(msg.Quantity)
-				c.TotalPrice += existingItem.Price * int64(msg.Quantity)
+				c.UpdateTotals()
 			} else {
 				c.mu.Lock()
 				c.lastItemId++
@@ -309,6 +311,9 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 				if msg.Tax > 0 {
 					tax = int(msg.Tax)
 				}
+				total := int(msg.Price) * int(msg.Quantity)
+				taxAmount := GetTaxAmount(total, tax)
+
 				c.Items = append(c.Items, &CartItem{
 					Id:          c.lastItemId,
 					ItemId:      int(msg.ItemId),
@@ -328,9 +333,9 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 					OrgPrice:    msg.OrgPrice,
 					ArticleType: msg.ArticleType,
 					Outlet:      msg.Outlet,
-					Tax:         tax,
+					Tax:         taxAmount,
 				})
-				c.TotalPrice += msg.Price * int64(msg.Quantity)
+				c.UpdateTotals()
 				c.mu.Unlock()
 			}
 
@@ -344,17 +349,18 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 			for i, item := range c.Items {
 				if item.Id == int(msg.Id) {
 					if msg.Quantity <= 0 {
-						c.TotalPrice -= item.Price * int64(item.Quantity)
+						//c.TotalPrice -= item.Price * int64(item.Quantity)
 						c.Items = append(c.Items[:i], c.Items[i+1:]...)
 					} else {
-						diff := int(msg.Quantity) - item.Quantity
+						//diff := int(msg.Quantity) - item.Quantity
 						item.Quantity = int(msg.Quantity)
-						c.TotalPrice += item.Price * int64(diff)
+						//c.TotalPrice += item.Price * int64(diff)
 					}
 
 					break
 				}
 			}
+			c.UpdateTotals()
 
 		}
 	case RemoveItemType:
@@ -366,13 +372,13 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 			items := make([]*CartItem, 0, len(c.Items))
 			for _, item := range c.Items {
 				if item.Id == int(msg.Id) {
-					c.TotalPrice -= item.Price * int64(item.Quantity)
+					//c.TotalPrice -= item.Price * int64(item.Quantity)
 				} else {
 					items = append(items, item)
 				}
 			}
 			c.Items = items
-
+			c.UpdateTotals()
 		}
 	case SetDeliveryType:
 		msg, ok := message.Content.(*messages.SetDelivery)
@@ -407,6 +413,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 					Items:    items,
 				})
 				c.Processing = true
+				c.UpdateTotals()
 				go func() {
 					time.Sleep(5 * time.Second)
 					c.Processing = false
@@ -429,7 +436,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 				}
 			}
 			c.Deliveries = deliveries
-
+			c.UpdateTotals()
 		}
 	case SetPickupPointType:
 		msg, ok := message.Content.(*messages.SetPickupPoint)
@@ -548,3 +555,19 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*FrameWithPa
 	msg := MakeFrameWithPayload(RemoteHandleMutationReply, 200, result)
 	return &msg, err
 }
+
+func (c *CartGrain) UpdateTotals() {
+	c.TotalPrice = 0
+	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)
+		itemDiff := max(0, item.OrgPrice-item.Price)
+		c.TotalDiscount += itemDiff * int64(item.Quantity)
+	}
+	for _, delivery := range c.Deliveries {
+		c.TotalPrice += delivery.Price
+	}
+
+}