Hello there, @racso.
Allow me to step in and provide some additional information about adding a subtotal to your estimates and invoices when using QuickBooks Desktop Pro 2018.
The screenshots and steps included on the first answer were for QuickBooks Enterprise. In Enterprise 15 and later version, you can add subtotal Quantity, Price, Cost, and numeric custom columns.
For QB Desktop Pro 2018, you still have the option to create an item for Subtotal, and edit your estimate to add this. Here's how to create an item:
- Click Lists.
- Choose Item List.
- Right-click on your mouse and choose New.
- For the Type of your item, choose Subtotal.
- Click OK to save changes.
Once done, you can go back to the created estimate and modify the transaction. For your guide, you can check this article as a reference: Create an estimate. You can also use the Memo field on the estimate to add important details.
Keep me posted if you have further questions about estimate or invoice. I'd be around to help you more. Have a good one.