diff --git a/modules/purchase_trade/purchase.py b/modules/purchase_trade/purchase.py
index 0090c56..dafaf88 100755
--- a/modules/purchase_trade/purchase.py
+++ b/modules/purchase_trade/purchase.py
@@ -1366,7 +1366,7 @@ class Line(metaclass=PoolMeta):
                             price = Decimal(cp.get_last_price())
                             logger.info("PRICE:%s",price)
                             if t.payable_rule:
-                                payable_price = t.payable_rule.compute_payable_quantity(grade) *  price / Decimal(100)
+                                payable_price = t.payable_rule.compute_payable_quantity(grade) *  ((Decimal(100) / Decimal(grade)) * price) / Decimal(100)
                             
                     t.manual_price = round(payable_price - penalty_price,2)
                     t.currency = self.purchase.currency