diff --git a/bp/cart/__init__.py b/bp/cart/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/bp/cart/services/__init__.py b/bp/cart/services/__init__.py
new file mode 100644
index 0000000..80dd875
--- /dev/null
+++ b/bp/cart/services/__init__.py
@@ -0,0 +1 @@
+from .total import total
diff --git a/bp/cart/services/total.py b/bp/cart/services/total.py
new file mode 100644
index 0000000..15e074f
--- /dev/null
+++ b/bp/cart/services/total.py
@@ -0,0 +1,6 @@
+def total(cart):
+    return sum(
+        (item.product.special_price or item.product.regular_price) * item.quantity
+        for item in cart
+        if (item.product.special_price or item.product.regular_price) is not None
+    )