Product with multiple packaging/UoM options

If we sell a product that is supplied/packaged in different quantities/UoM, how should this product be entered into the item master? For example, I have carbon nanotubes sold in bottles, either in a 10 gram bottle or a 2 gram bottle.

  1. Should I make new UoM called 10g and 2g and then should I make two individual items (with the same title: cabon nanotube) and set uom as “10g” and “2g” respectively?

  2. Is there a way to fit those two related products into 1 item master, and still be able to show the different packings using the predefined UoMs built-in available for sale?

The first way is easy enough, but it splits the product into two individual items and also makes a big mess in the UoM listing. I tried the second way using the UoM table on item master, but I get an error when I try to enter 10 for conversion factor, and Grams as UoM, that Conversion factor for default Unit of Measure must be 1 in row 1. This is after I set default UoM to Grams.

How do I handle this? I must be doing something wrong

I want to be able to show on my sales orders/invoices/etc to my customer that they bought a 10g or 2g item, and show the correct quantity for each. They could be buying in a single sales order carbon nanotubes, 10g, quantity 3, and then also carbon nanotubes, 2g, quantity 4.

Any advice is appreciated. Thanks

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I would set it up as follows:

One item, set Stock UOM to be grams. Create your UOMs:

  • Gram (conversion factor = 1)
  • 2g Bottle (conversion factor = 2)
  • 10g Bottle (conversion factor = 10)

When you create purchase orders/sales orders etc, you will be able to set the UOM of the sale. You could indicate that the customer bought a 10g bottle, or a 2g bottle, or a combination of the two.

There is a challenge with this though. The 10g and 2g are using different bottles, so if you need to order the bottles to package them, that could be a problem. You might be better off doing something like this:


  • Carbon nanotubes
  • UOM: Gram
  • Used to keep track of the mass of unpackaged nanotubes you have
  • 2g Bottle
  • UOM: Unit / Case
  • Used to purchase the bottles needed to store the 2g nanotubes
  • 10g Bottle
  • UOM: Unit / Case
  • Used to purchase the bottles needed to store the 10g nanotubes
  • 2g Bottle with Carbon Nanotubes
  • UOM: Unit / Case
  • Used to sell to customers a bottle with 2g of nanotubes in it
  • 10g Bottle with Carbon Nanotubes
  • UOM: Unit / Case
  • Used to sell to customers a bottle with 10g of nanotubes in it

You can then create BOMs that take 10g of CNTs and one unit of the 10g Bottle to make a 10g Bottle with CNTs in it (and for the 2g as well).

Hi, @Ben_Cornwell_Mott . Thanks for your quick response.

Thankfully, we do not need to do any packaging for the CNTs, so we do not need to purchase bottles or pack them with CNTs. We just get them packaged and sealed from the manufacturer in those quantities.

I tried your first solution and it seems OK but might be prone to error for our users down the line. The way pricing works for our 2g and 10g bottles of CNTs is that we have specific prices for each, and no price/gram.

So, if we were to follow this solution, firstly there didn’t seem to be a way to select UOM for the sale order as you indicated. I was able to fix that by customizing Sales Order Item form to show uom in the table on Sales Order in order to enable the UOM selection for sales orders. Was this how you meant that you could be able to set the UOM of the sale or was there another way?

Further, once we add the CNT item as a line item on the sales order, the pricing retrieved is for the default unit: Grams. We do have pricing for 2g and 10g, but no pricing for $/gram as it stands. Correct me if I’m wrong, but the price would have to be entered into the price lists as a fraction of the 10g price (lets say it is $315 for 10g as an example), then 1 Gram would be $31.50 for 10g to be correct. This also assumes that the 2g price will be on the same ratio: that 2g is $63.00 (2 * 1 Gram price), however this may not always be the case.

In conclusion, is it not better to just two separate items for each CNT? One item will be CNT 2g for $80 (not $63), and the other will be CNT 10g for $315. All this means is that my list of UoM will be very haphazard down the line when I have 1g 2g 3g 4g 5g … and so on added as needed. So do you think is this the best way to do this or maybe there is another better way?

You’ve discovered a couple of the issues ERPNext currently has. There is work to add separate item prices for UOM and quantities, but that’s not released yet. Enabling the UOM selection on sales orders the way you did is correct.

Going with separate items for now is probably the best way to go for now.

Thanks for confirming Ben. It’s good to know that its something being looked at for the future. We will go with separate items for now as it shouldn’t be a problem.

Suppose i have purchased (Metal Sheet) in “Kgs” and i have to maintain its stock in “Nos”. I have put conversion factor and that is calculating my Stock UOM in fractions but i want this to be whole number.

Please help. Thanks.