# Set up product units of measure in WMS
URL: https://support.starshipit.com/articles/14700000000069-set-up-product-units-of-measure-in-wms
Canonical: https://support.starshipit.com/articles/14700000000069-set-up-product-units-of-measure-in-wms
Markdown: https://support.starshipit.com/articles/14700000000069-set-up-product-units-of-measure-in-wms.md
Updated: 2026-11-08

> For the complete documentation index, see [llms.txt](https://support.starshipit.com/llms.txt).

> Link carton or case SKUs to a parent product, set their conversion quantity and verify inventory in base units.

Link a child SKU to a parent product when you buy or sell the same stock in different pack sizes. WMS records inventory against the parent and converts child quantities into that base unit.

## Before you begin

You need permission to manage products. Create the parent product first and decide which unit is the base inventory unit. The parent and child must belong to the same client. Check existing stock and open work before changing a product relationship or conversion.

## Choose the base unit

For example, use an individual bottle as the parent product and a case of 24 bottles as the child SKU. A child quantity of `2` then represents `48` parent units. Give each sellable pack size its own SKU and a distinct barcode so workers can identify the unit being scanned.

## Link the child product

1. Open **Products** and open the child SKU for editing, or add a new product.
2. On **Details**, find **Parent Product (optional)** and select the base-unit product.
3. Set **Conversion Quantity** to the number of parent units in one child unit, such as `24`. Use a whole number of at least `1`.
4. Set **UoM Label**, such as `CARTON`.
5. Select **Save changes**, or **Create Product** for a new SKU.
6. Reopen the product and confirm the parent, conversion quantity and unit label.

## Verify the conversion

Check a representative receipt or controlled order using the child SKU. Compare its selling-unit quantity with the parent-unit inventory movement. Do not add separate starting stock to both the parent and child for the same physical units. [Load opening inventory against the parent product](/articles/14700000000049-migrate-starting-stock-and-cut-over-to-starshipit-wms).

## Import units of measure by CSV

Use `parentProductSku`, `conversionQuantity` and `uomLabel` in the [Product CSV reference](/articles/14700000000041-import-and-export-wms-data-by-csv). The parent can already exist or appear in the same file. Start from a current export so other fields retain their intended values.

## Troubleshooting

If the parent cannot be selected or the save fails, check the client ownership, parent relationship and conversion quantity. If balances do not match the physical stock, review the parent-unit movements before making another adjustment.

## Related articles

* [Configure WMS products and inventory](/articles/14700000000006-configure-wms-products-and-inventory)
* [Migrate starting stock and cut over to Starshipit WMS](/articles/14700000000049-migrate-starting-stock-and-cut-over-to-starshipit-wms)
* [View inventory and stock levels](/articles/14700000000014-view-inventory-and-stock-levels)