I'm here to help you customize the invoice in QuickBooks Desktop, Heritreas.

Being able to include a formula to add the units shown on the quantity column isn't an option. However, you can edit the invoice template to add more columns for the data that matters to you.

Let me show you how:

1. Go to the Lists menu, then select Item List.
2. Choose the invoice template.
3. Right-click and select Edit Template. The Basic Customization window will open.
4. Click the Additional Customization button. The Additional Customization window will open.
5. Go to the Columns section.
6. Mark boxes labeled Other 1 or Other 2.
7. Under the Title column, type the name of the column.
8. Click the OK button.
9. Click OK to exit.

I'm also glad to let you know that Airy new is added to our program. 

Keep me posted if you need more help customizing your sales forms in QuickBooks. I'm always around to help you.