diff --git a/htdocs/bom/bom_card.php b/htdocs/bom/bom_card.php
index 4a919d7bb2a..887a319aefe 100644
--- a/htdocs/bom/bom_card.php
+++ b/htdocs/bom/bom_card.php
@@ -68,7 +68,6 @@ if (empty($action) && empty($id) && empty($ref)) $action = 'view';
 
 // Load object
 include DOL_DOCUMENT_ROOT.'/core/actions_fetchobject.inc.php'; // Must be include, not include_once.
-$object->calculateCosts();
 
 // Security check - Protection if external user
 //if ($user->socid > 0) accessforbidden();
@@ -524,7 +523,8 @@ if ($object->id > 0 && (empty($action) || ($action != 'edit' && $action != 'crea
 	$keyforbreak = 'duration';
 	include DOL_DOCUMENT_ROOT.'/core/tpl/commonfields_view.tpl.php';
 
-	print '<td>Coût total</td><td>'.price($object->total_cost).'</td>';
+	print '<tr><td>'.$langs->trans("TotalCost").'</td><td>'.price($object->total_cost).'</td></tr>';
+	print '<tr><td>'.$langs->trans("UnitCost").'</td><td>'.price($object->unit_cost).'</td></tr>';
 
 	// Other attributes
 	include DOL_DOCUMENT_ROOT.'/core/tpl/extrafields_view.tpl.php';
@@ -545,9 +545,6 @@ if ($object->id > 0 && (empty($action) || ($action != 'edit' && $action != 'crea
 
 	if (!empty($object->table_element_line))
 	{
-	    // Show object lines
-	    $result = $object->getLinesArray();
-
 	    print '	<form name="addproduct" id="addproduct" action="'.$_SERVER["PHP_SELF"].'?id='.$object->id.(($action != 'editline') ? '#addline' : '#line_'.GETPOST('lineid', 'int')).'" method="POST">
     	<input type="hidden" name="token" value="' . newToken().'">
     	<input type="hidden" name="action" value="' . (($action != 'editline') ? 'addline' : 'updateline').'">
diff --git a/htdocs/bom/class/bom.class.php b/htdocs/bom/class/bom.class.php
index 5e25ef7fb14..ea47b39dad2 100644
--- a/htdocs/bom/class/bom.class.php
+++ b/htdocs/bom/class/bom.class.php
@@ -166,6 +166,16 @@ class BOM extends CommonObject
 	 */
 	public $lines = array();
 
+	/**
+	 * @var int		Calculated cost for the BOM
+	 */
+	public $total_cost = 0;
+
+	/**
+	 * @var int		Calculated cost for 1 unit of the product in BOM
+	 */
+	public $unit_cost = 0;
+
 
 
 	/**
@@ -324,6 +334,7 @@ class BOM extends CommonObject
 	{
 		$result = $this->fetchCommon($id, $ref);
 		if ($result > 0 && !empty($this->table_element_line)) $this->fetchLines();
+		$this->calculateCosts();
 		return $result;
 	}
 
@@ -912,7 +923,6 @@ class BOM extends CommonObject
 	    else
 	    {
 	        $this->lines = $result;
-	        $this->calculateCosts();
 	        return $this->lines;
 	    }
 	}
@@ -993,17 +1003,25 @@ class BOM extends CommonObject
 		return $error;
 	}
 
+	/**
+	 * BOM costs calculation based on cost_price or pmp of each BOM line
+	 */
 	public function calculateCosts() {
 		include_once DOL_DOCUMENT_ROOT . '/product/class/product.class.php';
+		$this->unit_cost = 0;
 		$this->total_cost = 0;
+
 		foreach ($this->lines as &$line) {
 			$tmpproduct = new Product($this->db);
 			$tmpproduct->fetch($line->fk_product);
 
-			$line->unit_cost = $tmpproduct->cost_price; // TODO : add option to work with cost_price or pmp
-			$line->total_cost = price2num($line->qty * $line->unit_cost);
+			$line->unit_cost = (!empty($tmpproduct->cost_price)) ? $tmpproduct->cost_price : $tmpproduct->pmp; // TODO : add option to work with cost_price or pmp
+			$line->total_cost = price2num($line->qty * $line->unit_cost, 'MT');
 			$this->total_cost += $line->total_cost;
 		}
+
+		$this->total_cost = price2num($this->total_cost, 'MT');
+		$this->unit_cost = price2num($this->total_cost / $this->qty, 'MU');
 	}
 }
 
@@ -1086,6 +1104,16 @@ class BOMLine extends CommonObjectLine
 	public $import_key;
 	// END MODULEBUILDER PROPERTIES
 
+	/**
+	 * @var int		Calculated cost for the BOM line
+	 */
+	public $total_cost = 0;
+
+	/**
+	 * @var int		Line unit cost based on product cost price or pmp
+	 */
+	public $unit_cost = 0;
+
 
 	/**
 	 * Constructor
diff --git a/htdocs/langs/en_US/mrp.lang b/htdocs/langs/en_US/mrp.lang
index 41be1d993b8..4e653e04409 100644
--- a/htdocs/langs/en_US/mrp.lang
+++ b/htdocs/langs/en_US/mrp.lang
@@ -70,4 +70,6 @@ ProductQtyToConsumeByMO=Product quantity still to consume by open MO
 ProductQtyToProduceByMO=Product quentity still to produce by open MO
 AddNewConsumeLines=Add new line to consume
 ProductsToConsume=Products to consume
-ProductsToProduce=Products to produce
\ No newline at end of file
+ProductsToProduce=Products to produce
+UnitCost=Unit cost
+TotalCost=Total cost