diff --git a/src/pages/09_task-order/expansion/ProductExpansion.vue b/src/pages/09_task-order/expansion/ProductExpansion.vue
index 32d69f8c..e5fe1d34 100644
--- a/src/pages/09_task-order/expansion/ProductExpansion.vue
+++ b/src/pages/09_task-order/expansion/ProductExpansion.vue
@@ -55,7 +55,7 @@ function openList(index: number) {
 
 function calcPricePerUnit(product: RequestWork['productService']['product']) {
   return product.vatIncluded
-    ? precisionRound(product.serviceCharge / (1 + (config.value?.vat || 0.07)))
+    ? product.serviceCharge / (1 + (config.value?.vat || 0.07))
     : product.serviceCharge;
 }
 
@@ -63,21 +63,17 @@ function calcPrice(
   product: RequestWork['productService']['product'],
   amount: number,
 ) {
-  const disc =
+  const pricePerUnit = product.serviceCharge;
+  const discount =
     taskProduct.value.find((v) => v.productId === product.id)?.discount || 0;
-  const pricePerUnit = calcPricePerUnit(product);
+  const priceNoVat = product.vatIncluded
+    ? pricePerUnit / (1 + (config.value?.vat || 0.07))
+    : pricePerUnit;
+  const priceDiscountNoVat = priceNoVat * amount - discount;
 
-  return precisionRound(
-    pricePerUnit * amount -
-      disc +
-      precisionRound(
-        product.calcVat
-          ? (pricePerUnit * (disc ? amount : 1) - disc) *
-              (config.value?.vat || 0.07)
-          : 0,
-      ) *
-        (!disc ? amount : 1),
-  );
+  const rawVatTotal = priceDiscountNoVat * (config.value?.vat || 0.07);
+
+  return precisionRound(priceNoVat * amount + rawVatTotal);
 }
 </script>
 <template>