diff --git a/erpnext/projects/doctype/project/project.js b/erpnext/projects/doctype/project/project.js
index f366f77..2dac399 100644
--- a/erpnext/projects/doctype/project/project.js
+++ b/erpnext/projects/doctype/project/project.js
@@ -68,6 +68,10 @@
 				frm.events.create_duplicate(frm);
 			}, __("Actions"));
 
+			frm.add_custom_button(__('Update Total Purchase Cost'), () => {
+				frm.events.update_total_purchase_cost(frm);
+			}, __("Actions"));
+
 			frm.trigger("set_project_status_button");
 
 
@@ -92,6 +96,22 @@
 
 	},
 
+	update_total_purchase_cost: function(frm) {
+		frappe.call({
+			method: "erpnext.projects.doctype.project.project.recalculate_project_total_purchase_cost",
+			args: {project: frm.doc.name},
+			freeze: true,
+			freeze_message: __('Recalculating Purchase Cost against this Project...'),
+			callback: function(r) {
+				if (r && !r.exc) {
+					frappe.msgprint(__('Total Purchase Cost has been updated'));
+					frm.refresh();
+				}
+			}
+
+		});
+	},
+
 	set_project_status_button: function(frm) {
 		frm.add_custom_button(__('Set Project Status'), () => {
 			let d = new frappe.ui.Dialog({
diff --git a/erpnext/projects/doctype/project/project.py b/erpnext/projects/doctype/project/project.py
index e9aed1a..4f2e395 100644
--- a/erpnext/projects/doctype/project/project.py
+++ b/erpnext/projects/doctype/project/project.py
@@ -4,11 +4,11 @@
 
 import frappe
 from email_reply_parser import EmailReplyParser
-from frappe import _
+from frappe import _, qb
 from frappe.desk.reportview import get_match_cond
 from frappe.model.document import Document
 from frappe.query_builder import Interval
-from frappe.query_builder.functions import Count, CurDate, Date, UnixTimestamp
+from frappe.query_builder.functions import Count, CurDate, Date, Sum, UnixTimestamp
 from frappe.utils import add_days, flt, get_datetime, get_time, get_url, nowtime, today
 from frappe.utils.user import is_website_user
 
@@ -249,12 +249,7 @@
 			self.per_gross_margin = (self.gross_margin / flt(self.total_billed_amount)) * 100
 
 	def update_purchase_costing(self):
-		total_purchase_cost = frappe.db.sql(
-			"""select sum(base_net_amount)
-			from `tabPurchase Invoice Item` where project = %s and docstatus=1""",
-			self.name,
-		)
-
+		total_purchase_cost = calculate_total_purchase_cost(self.name)
 		self.total_purchase_cost = total_purchase_cost and total_purchase_cost[0][0] or 0
 
 	def update_sales_amount(self):
@@ -695,3 +690,29 @@
 
 def get_users_email(doc):
 	return [d.email for d in doc.users if frappe.db.get_value("User", d.user, "enabled")]
+
+
+def calculate_total_purchase_cost(project: str | None = None):
+	if project:
+		pitem = qb.DocType("Purchase Invoice Item")
+		frappe.qb.DocType("Purchase Invoice Item")
+		total_purchase_cost = (
+			qb.from_(pitem)
+			.select(Sum(pitem.base_net_amount))
+			.where((pitem.project == project) & (pitem.docstatus == 1))
+			.run(as_list=True)
+		)
+		return total_purchase_cost
+	return None
+
+
+@frappe.whitelist()
+def recalculate_project_total_purchase_cost(project: str | None = None):
+	if project:
+		total_purchase_cost = calculate_total_purchase_cost(project)
+		frappe.db.set_value(
+			"Project",
+			project,
+			"total_purchase_cost",
+			(total_purchase_cost and total_purchase_cost[0][0] or 0),
+		)