diff --git a/erpnext/manufacturing/doctype/production_plan/production_plan.py b/erpnext/manufacturing/doctype/production_plan/production_plan.py
index 3524283db1c..a5b8ec870f3 100644
--- a/erpnext/manufacturing/doctype/production_plan/production_plan.py
+++ b/erpnext/manufacturing/doctype/production_plan/production_plan.py
@@ -962,6 +962,7 @@ class ProductionPlan(Document):
 		"Fetch sub assembly items and optionally combine them."
 		self.sub_assembly_items = []
 		sub_assembly_items_store = []  # temporary store to process all subassembly items
+		bin_details = frappe._dict()
 
 		for row in self.po_items:
 			if self.skip_available_sub_assembly_item and not self.sub_assembly_warehouse:
@@ -977,6 +978,7 @@ class ProductionPlan(Document):
 
 			get_sub_assembly_items(
 				[item.production_item for item in sub_assembly_items_store],
+				bin_details,
 				row.bom_no,
 				bom_data,
 				row.planned_qty,
@@ -1777,6 +1779,7 @@ def get_item_data(item_code):
 
 def get_sub_assembly_items(
 	sub_assembly_items,
+	bin_details,
 	bom_no,
 	bom_data,
 	to_produce_qty,
@@ -1791,25 +1794,27 @@ def get_sub_assembly_items(
 			parent_item_code = frappe.get_cached_value("BOM", bom_no, "item")
 			stock_qty = (d.stock_qty / d.parent_bom_qty) * flt(to_produce_qty)
 
-			bin_details = frappe._dict()
 			if skip_available_sub_assembly_item and d.item_code not in sub_assembly_items:
-				bin_details = get_bin_details(d, company, for_warehouse=warehouse)
+				bin_details.setdefault(d.item_code, get_bin_details(d, company, for_warehouse=warehouse))
 
-				for _bin_dict in bin_details:
+				for _bin_dict in bin_details[d.item_code]:
 					if _bin_dict.projected_qty > 0:
-						if _bin_dict.projected_qty > stock_qty:
+						if _bin_dict.projected_qty >= stock_qty:
+							_bin_dict.projected_qty -= stock_qty
 							stock_qty = 0
 							continue
 						else:
 							stock_qty = stock_qty - _bin_dict.projected_qty
 			elif warehouse:
-				bin_details = get_bin_details(d, company, for_warehouse=warehouse)
+				bin_details.setdefault(d.item_code, get_bin_details(d, company, for_warehouse=warehouse))
 
 			if stock_qty > 0:
 				bom_data.append(
 					frappe._dict(
 						{
-							"actual_qty": bin_details[0].get("actual_qty", 0) if bin_details else 0,
+							"actual_qty": bin_details[d.item_code][0].get("actual_qty", 0)
+							if bin_details
+							else 0,
 							"parent_item_code": parent_item_code,
 							"description": d.description,
 							"production_item": d.item_code,
@@ -1828,6 +1833,7 @@ def get_sub_assembly_items(
 				if d.value:
 					get_sub_assembly_items(
 						sub_assembly_items,
+						bin_details,
 						d.value,
 						bom_data,
 						stock_qty,
diff --git a/erpnext/manufacturing/doctype/production_plan/test_production_plan.py b/erpnext/manufacturing/doctype/production_plan/test_production_plan.py
index eefd577e9e6..7c1dba8be91 100644
--- a/erpnext/manufacturing/doctype/production_plan/test_production_plan.py
+++ b/erpnext/manufacturing/doctype/production_plan/test_production_plan.py
@@ -1848,6 +1848,64 @@ class TestProductionPlan(IntegrationTestCase):
 			self.assertEqual(row.production_item, sf_item)
 			self.assertEqual(row.qty, 5.0)
 
+	def test_calculation_of_sub_assembly_items(self):
+		make_item("Sub Assembly Item ", properties={"is_stock_item": 1})
+		make_item("RM Item 1", properties={"is_stock_item": 1})
+		make_item("RM Item 2", properties={"is_stock_item": 1})
+		make_bom(item="Sub Assembly Item", raw_materials=["RM Item 1", "RM Item 2"])
+		make_bom(item="_Test FG Item", raw_materials=["Sub Assembly Item", "RM Item 1"])
+		make_bom(item="_Test FG Item 2", raw_materials=["Sub Assembly Item"])
+
+		from erpnext.stock.doctype.stock_entry.stock_entry_utils import make_stock_entry
+
+		make_stock_entry(
+			item_code="Sub Assembly Item",
+			qty=80,
+			purpose="Material Receipt",
+			to_warehouse="_Test Warehouse - _TC",
+		)
+		make_stock_entry(
+			item_code="RM Item 1", qty=90, purpose="Material Receipt", to_warehouse="_Test Warehouse - _TC"
+		)
+
+		plan = create_production_plan(
+			skip_available_sub_assembly_item=1,
+			sub_assembly_warehouse="_Test Warehouse - _TC",
+			warehouse="_Test Warehouse - _TC",
+			item_code="_Test FG Item",
+			skip_getting_mr_items=1,
+			planned_qty=100,
+			do_not_save=1,
+		)
+		plan.get_items_from = ""
+		plan.append(
+			"po_items",
+			{
+				"use_multi_level_bom": 1,
+				"item_code": "_Test FG Item 2",
+				"bom_no": frappe.db.get_value("Item", "_Test FG Item 2", "default_bom"),
+				"planned_qty": 50,
+				"planned_start_date": now_datetime(),
+				"stock_uom": "Nos",
+				"warehouse": "_Test Warehouse - _TC",
+			},
+		)
+		plan.save()
+
+		plan.get_sub_assembly_items()
+
+		self.assertEqual(plan.sub_assembly_items[0].qty, 20)
+		self.assertEqual(plan.sub_assembly_items[1].qty, 50)
+
+		from erpnext.manufacturing.doctype.production_plan.production_plan import (
+			get_items_for_material_requests,
+		)
+
+		mr_items = get_items_for_material_requests(plan.as_dict())
+
+		self.assertEqual(mr_items[0].get("quantity"), 80)
+		self.assertEqual(mr_items[1].get("quantity"), 70)
+
 
 def create_production_plan(**args):
 	"""