diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index 6410bb16d09..b41a41149bf 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -1023,15 +1023,38 @@ class stock_move(osv.osv):
                 'message': 'You are moving %.2f products but only %.2f available in this lot.' % (product_qty, prodlot.stock_available or 0.0)
             }
         return {'warning': warning}
-
+    
+    def onchange_quantity(self, cr, uid, ids, product_id, product_qty, product_uom, product_uos):
+        result = {
+                  'product_uos_qty': 0.00
+          }
+        
+        if (not product_id) or (product_qty <=0.0):
+            return {'value': result}
+            
+        product_obj = self.pool.get('product.product')
+        uos_coeff = product_obj.read(cr, uid, product_id, ['uos_coeff'])
+        
+        if product_uos and product_uom and (product_uom != product_uos):
+            result['product_uos_qty'] = product_qty * uos_coeff['uos_coeff']
+        else:
+            result['product_uos_qty'] = product_qty
+        
+        return {'value': result}
+    
     def onchange_product_id(self, cr, uid, ids, prod_id=False, loc_id=False, loc_dest_id=False):
         if not prod_id:
             return {}
         product = self.pool.get('product.product').browse(cr, uid, [prod_id])[0]
+        uos_id  = product.uos_id and product.uos_id.id or False
         result = {
             'name': product.name,
             'product_uom': product.uom_id.id,
+            'product_uos': uos_id,
+            'product_qty': 1.00,
+            'product_uos_qty' : self.pool.get('stock.move').onchange_quantity(cr, uid, ids, prod_id, 1.00, product.uom_id.id, uos_id)['value']['product_uos_qty']
         }
+        
         if loc_id:
             result['location_id'] = loc_id
         if loc_dest_id:
diff --git a/addons/stock/stock_view.xml b/addons/stock/stock_view.xml
index ca2aeeb4f3e..2f6eb80fd87 100644
--- a/addons/stock/stock_view.xml
+++ b/addons/stock/stock_view.xml
@@ -535,9 +535,9 @@
                                     <field name="location_id" select="1" domain="[('usage','=','internal')]"/>
                                     <field name="location_dest_id" select="1" domain="[('usage','=','internal')]"/>
                                     <field colspan="4" context="location=location_id" name="product_id" on_change="onchange_product_id(product_id, location_id, location_dest_id)" select="1"/>
-                                    <field name="product_qty" select="1"/>
+                                    <field name="product_qty" select="1" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field name="product_uom" select="1"/>
-                                    <field groups="product.group_uos" name="product_uos"/>
+                                    <field groups="product.group_uos" name="product_uos" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field groups="product.group_uos" name="product_uos_qty"/>
                                     <field colspan="4" invisible="1" name="name" select="1"/>
                                     <field invisible="1" name="date"/>
@@ -634,9 +634,9 @@
                                     <field name="location_id" select="1" domain="[('usage','=','internal')]"/>
                                     <field name="location_dest_id" select="1" domain="[('usage','&lt;&gt;','view')]"/>
                                     <field colspan="4" context="location=location_id" name="product_id" on_change="onchange_product_id(product_id, location_id, location_dest_id)" select="1"/>
-                                    <field name="product_qty" select="1"/>
+                                    <field name="product_qty" select="1" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field name="product_uom" select="1"/>
-                                    <field groups="product.group_uos" name="product_uos"/>
+                                    <field groups="product.group_uos" name="product_uos" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field groups="product.group_uos" name="product_uos_qty"/>
                                     <field colspan="4" invisible="1" name="name" select="1"/>
                                     <field invisible="1" name="date"/>
@@ -827,9 +827,9 @@
                                     <field name="location_id" select="1" domain="[('usage','=','internal')]"/>
                                     <field name="location_dest_id" select="1" domain="[('usage','&lt;&gt;','view')]"/>
                                     <field colspan="4" context="location=location_id" name="product_id" on_change="onchange_product_id(product_id, location_id, location_dest_id)" select="1"/>
-                                    <field name="product_qty" select="1"/>
+                                    <field name="product_qty" select="1" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)" />
                                     <field name="product_uom" select="1"/>
-                                    <field groups="product.group_uos" name="product_uos"/>
+                                    <field groups="product.group_uos" name="product_uos" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field groups="product.group_uos" name="product_uos_qty"/>
                                     <field colspan="4" invisible="1" name="name" select="1"/>
                                     <field invisible="1" name="date"/>
@@ -1016,9 +1016,9 @@
                                     <field name="location_id" select="1" domain="[('usage','&lt;&gt;','view')]"/>
                                     <field domain="[('usage','=','internal')]" name="location_dest_id" select="1"/>
                                     <field colspan="4" context="location=location_id" name="product_id" on_change="onchange_product_id(product_id, location_id, location_dest_id)" select="1"/>
-                                    <field name="product_qty" select="1"/>
+                                    <field name="product_qty" select="1" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field name="product_uom" select="1"/>
-                                    <field groups="product.group_uos" name="product_uos"/>
+                                    <field groups="product.group_uos" name="product_uos" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                                     <field groups="product.group_uos" name="product_uos_qty"/>
                                     <field colspan="4" invisible="1" name="name" select="1"/>
                                     <field groups="base.group_extended" name="date_planned"/>
@@ -1214,7 +1214,7 @@
                 <tree color="grey:state=='cancel'" string="Moves">
                     <field name="name"/>
                     <field name="product_id"/>
-                    <field name="product_qty"/>
+                    <field name="product_qty" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                     <field name="product_uom" string="UOM"/>
                     <field name="picking_id" select="1"/>
                     <field name="prodlot_id"/>
@@ -1239,7 +1239,7 @@
                     <field name="location_id" select="1"/>
                     <field name="location_dest_id" select="1"/>
                     <field colspan="4" name="product_id" select="1"/>
-                    <field name="product_qty" select="2"/>
+                    <field name="product_qty" select="2" on_change="onchange_quantity(product_id, product_qty, product_uom, product_uos)"/>
                     <field name="product_uom" select="2"/>
                     <field colspan="4" name="name" select="2"/>
                     <field name="date"/>