# Product unit price from a lot

**URL:** <https://www.dolibarr.org/forum/t/product-unit-price-from-a-lot/21483>\
**Category:** PM modules\
**Tags:** Products, Question, Help\
**Created:** [November 23, 2021, 6:02pm UTC](https://www.dolibarr.org/forum/t/product-unit-price-from-a-lot/21483 "2021-11-23T18:02:51Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![mr.white](https://www.dolibarr.org/forum/letter_avatar_proxy/v4/letter/m/45deac/32.png) [@mr.white](https://www.dolibarr.org/forum/u/mr.white)\
**Post date:** [November 23, 2021, 6:02pm UTC](https://www.dolibarr.org/forum/t/product-unit-price-from-a-lot/21483/1 "2021-11-23T18:02:51Z")

</div>

How to make that dolibarr calculate the price of a stone, bought with a lot made up of different stones that have different dimensions, weight and number of pieces, while the purchase price is calculated based on the total weight.

To understand better I have attached an image of how the calculation should be done

 ![esempio_pietre](https://www.dolibarr.org/forum/uploads/dolibarrorg/original/2X/e/eecb0921127e68f53c9bb750413bae5a409dafdc.jpeg)

Thanks