diff --git a/setup/stock_packaging_calculator/odoo/addons/stock_packaging_calculator b/setup/stock_packaging_calculator/odoo/addons/stock_packaging_calculator
new file mode 120000
index 000000000..d3e128c8d
--- /dev/null
+++ b/setup/stock_packaging_calculator/odoo/addons/stock_packaging_calculator
@@ -0,0 +1 @@
+../../../../stock_packaging_calculator
\ No newline at end of file
diff --git a/setup/stock_packaging_calculator/setup.py b/setup/stock_packaging_calculator/setup.py
new file mode 100644
index 000000000..28c57bb64
--- /dev/null
+++ b/setup/stock_packaging_calculator/setup.py
@@ -0,0 +1,6 @@
+import setuptools
+
+setuptools.setup(
+    setup_requires=['setuptools-odoo'],
+    odoo_addon=True,
+)
diff --git a/stock_packaging_calculator/__init__.py b/stock_packaging_calculator/__init__.py
new file mode 100644
index 000000000..0650744f6
--- /dev/null
+++ b/stock_packaging_calculator/__init__.py
@@ -0,0 +1 @@
+from . import models
diff --git a/stock_packaging_calculator/__manifest__.py b/stock_packaging_calculator/__manifest__.py
new file mode 100644
index 000000000..4399bba90
--- /dev/null
+++ b/stock_packaging_calculator/__manifest__.py
@@ -0,0 +1,15 @@
+# Copyright 2020 Camptocamp SA
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
+{
+    "name": "Stock packaging calculator",
+    "summary": "Compute product quantity to pick by packaging",
+    "version": "13.0.1.0.0",
+    "development_status": "Alpha",
+    "category": "Warehouse Management",
+    "website": "https://github.com/OCA/stock-logistics-warehouse",
+    "author": "Camptocamp, Odoo Community Association (OCA)",
+    "license": "AGPL-3",
+    "application": False,
+    "installable": True,
+    "depends": ["product"],
+}
diff --git a/stock_packaging_calculator/models/__init__.py b/stock_packaging_calculator/models/__init__.py
new file mode 100644
index 000000000..9649db77a
--- /dev/null
+++ b/stock_packaging_calculator/models/__init__.py
@@ -0,0 +1 @@
+from . import product
diff --git a/stock_packaging_calculator/models/product.py b/stock_packaging_calculator/models/product.py
new file mode 100644
index 000000000..5dd73bac3
--- /dev/null
+++ b/stock_packaging_calculator/models/product.py
@@ -0,0 +1,51 @@
+# Copyright 2020 Camptocamp SA
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
+
+from odoo import models
+from odoo.tools import float_compare
+
+
+class Product(models.Model):
+    _inherit = "product.product"
+
+    def product_qty_by_packaging(self, prod_qty, min_unit=None):
+        """Calculate quantity by packaging.
+
+        Limitation: fractional quantities are lost.
+
+        :prod_qty: total qty to satisfy.
+        :min_unit: minimal unit of measure as a tuple (qty, name).
+                   Default: to UoM unit.
+        :returns: list of tuple in the form [(qty_per_package, package_name)]
+
+        """
+        packagings = [(x.qty, x.name) for x in self.packaging_ids]
+        if min_unit is None:
+            # You can pass `False` to skip it.
+            single_unit = self.uom_id
+            min_unit = (single_unit.factor, single_unit.name)
+        if min_unit:
+            packagings.append(min_unit)
+        return self._product_qty_by_packaging(
+            sorted(packagings, reverse=True), prod_qty
+        )
+
+    def _product_qty_by_packaging(self, pkg_by_qty, qty):
+        """Produce a list of tuple of packaging qty and packaging name."""
+        # TODO: refactor to handle fractional quantities (eg: 0.5 Kg)
+        res = []
+        for pkg_qty, pkg in pkg_by_qty:
+            qty_per_pkg, qty = self._qty_by_pkg(pkg_qty, qty)
+            if qty_per_pkg:
+                res.append((qty_per_pkg, pkg))
+            if not qty:
+                break
+        return res
+
+    def _qty_by_pkg(self, pkg_qty, qty):
+        """Calculate qty needed for given package qty."""
+        qty_per_pkg = 0
+        while float_compare(qty - pkg_qty, 0.0, precision_digits=3) >= 0.0:
+            qty -= pkg_qty
+            qty_per_pkg += 1
+        return qty_per_pkg, qty
diff --git a/stock_packaging_calculator/readme/CONTRIBUTORS.rst b/stock_packaging_calculator/readme/CONTRIBUTORS.rst
new file mode 100644
index 000000000..f583948be
--- /dev/null
+++ b/stock_packaging_calculator/readme/CONTRIBUTORS.rst
@@ -0,0 +1 @@
+* Simone Orsi <simahawk@gmail.com>
diff --git a/stock_packaging_calculator/readme/DESCRIPTION.rst b/stock_packaging_calculator/readme/DESCRIPTION.rst
new file mode 100644
index 000000000..b470f8a94
--- /dev/null
+++ b/stock_packaging_calculator/readme/DESCRIPTION.rst
@@ -0,0 +1,18 @@
+
+Basic module providing an helper method to calculate the quantity of product by packaging.
+
+Imagine you have the following packagings:
+
+* Pallet: 1000 Units
+* Big box: 500 Units
+* Box: 50 Units
+
+and you have to pick from your warehouse 2860 Units.
+
+Then you can do:
+
+    >>> product.product_qty_by_packaging(2860)
+
+    [(2, "Pallet"), (1, "Big Box"), (7, "Box"), (10, "Units")]
+
+With this you can show a proper message to warehouse operators to quickly pick the quantity they need.
diff --git a/stock_packaging_calculator/readme/ROADMAP.rst b/stock_packaging_calculator/readme/ROADMAP.rst
new file mode 100644
index 000000000..e4881d5e6
--- /dev/null
+++ b/stock_packaging_calculator/readme/ROADMAP.rst
@@ -0,0 +1,4 @@
+TODO
+
+1. Fractional quantities (eg: 0.5 Kg) are lost when counting units
+2. Maybe rely on `packaging_uom`
diff --git a/stock_packaging_calculator/tests/__init__.py b/stock_packaging_calculator/tests/__init__.py
new file mode 100644
index 000000000..04c47e711
--- /dev/null
+++ b/stock_packaging_calculator/tests/__init__.py
@@ -0,0 +1 @@
+from . import test_packaging_calc
diff --git a/stock_packaging_calculator/tests/test_packaging_calc.py b/stock_packaging_calculator/tests/test_packaging_calc.py
new file mode 100644
index 000000000..c5836b941
--- /dev/null
+++ b/stock_packaging_calculator/tests/test_packaging_calc.py
@@ -0,0 +1,66 @@
+# Copyright 2020 Camptocamp SA
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
+from odoo.tests import SavepointCase
+
+
+class TestCalc(SavepointCase):
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.env = cls.env(context=dict(cls.env.context, tracking_disable=True))
+        cls.uom_unit = cls.env.ref("uom.product_uom_unit")
+        cls.uom_kg = cls.env.ref("uom.product_uom_kgm")
+        cls.product_a = cls.env["product.product"].create(
+            {
+                "name": "Product A",
+                "type": "product",
+                "uom_id": cls.uom_unit.id,
+                "uom_po_id": cls.uom_unit.id,
+            }
+        )
+        cls.pkg_box = cls.env["product.packaging"].create(
+            {"name": "Box", "product_id": cls.product_a.id, "qty": 50}
+        )
+        cls.pkg_big_box = cls.env["product.packaging"].create(
+            {"name": "Big Box", "product_id": cls.product_a.id, "qty": 200}
+        )
+        cls.pkg_pallet = cls.env["product.packaging"].create(
+            {"name": "Pallet", "product_id": cls.product_a.id, "qty": 2000}
+        )
+
+    def test_calc_1(self):
+        """Test easy behavior 1."""
+        self.assertEqual(
+            self.product_a.product_qty_by_packaging(2655),
+            [(1, "Pallet"), (3, "Big Box"), (1, "Box"), (5, self.uom_unit.name)],
+        )
+
+    def test_calc_2(self):
+        """Test easy behavior 2."""
+        self.assertEqual(
+            self.product_a.product_qty_by_packaging(350), [(1, "Big Box"), (3, "Box")]
+        )
+
+    def test_calc_3(self):
+        """Test easy behavior 3."""
+        self.assertEqual(
+            self.product_a.product_qty_by_packaging(80),
+            [(1, "Box"), (30, self.uom_unit.name)],
+        )
+
+    def test_calc_4(self):
+        """Test minimal unit override."""
+        self.assertEqual(
+            self.product_a.product_qty_by_packaging(80, min_unit=(5, "Pack 5")),
+            [(1, "Box"), (6, "Pack 5")],
+        )
+
+    def test_calc_5(self):
+        """Test no minimal unit."""
+        self.assertEqual(
+            self.product_a.product_qty_by_packaging(80, min_unit=False), [(1, "Box")]
+        )
+
+    def test_calc_6(self):
+        """Test fractional qty is lost."""
+        self.assertEqual(self.product_a.product_qty_by_packaging(50.5), [(1, "Box")])