Inventory · Odoo glossary
Units of Measure (UoM)
Understand units of measure, inventory and purchase conversions in Odoo, and how consistent quantities support purchasing, stock records and bills of materials.
Definition
In general ERP practice
A unit of measure (UoM) defines how a quantity is expressed, such as units, kilograms, litres or metres. A conversion factor relates compatible units so that the same physical quantity can be represented consistently in different documents.
The quantity and its unit belong together. A number without a unit is ambiguous, and converting between unlike dimensions, such as weight and volume, requires product-specific information rather than a universal factor.
In Odoo
Odoo lets a product use an inventory unit and purchase units, converting quantities between purchasing and warehouse documents. Purchase units must belong to the same category as the product’s default unit.
Odoo 19’s documentation groups the configuration under Units of Measure & Packagings. Sales packagings and vendor purchase units are configured on the product. A supplier’s commercial pack size and the warehouse’s counting unit therefore need a defined relationship, not separate inconsistent quantities.
Illustrative conversion
Purchase unit
One supplier carton contains 12 individual units.
Order quantity
Five cartons are purchased.
Inventory quantity
The receipt represents 60 units when the configured factor is 12.
Check the conversion before scaling
Verify the supplier pack size, product unit and conversion factor using a small representative order. The same physical quantity should be understandable across purchasing, receipts and component requirements; a conversion error can multiply into replenishment and manufacturing demand.
Official Odoo documentation
The Odoo-specific explanation above is based on the documentation for Odoo 19. Features and workflows can differ in other versions.
Related glossary terms
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