Hi there, @ggrenovation.

Thank you for joining the Community. I'd be happy to help walk you through adding a subtotal line item in an estimate in QuickBooks Desktop.

To start, let's create a subtotal item. Here's how: 

1. From the Lists menu, select Item List.
2. Click Item, then select New.
3. Under TYPE drop-down, select Subtotal. 
4. Enter the item's information.
5. Click OK.

After that, let me show you how to add the new item when you create an estimate: 

1. From the Customers menu, select Create Estimates. 
2. Fill in the relevant information on the form like the Customer's name, Date and Estimate #.
3. In the detail area, select the item(s) you propose to do or include as a sale.
4. If you want to apply Subtotal, click the drop-down under the ITEM column and select it. 
5. Select Save & Close.

For additional reference, I've also attached an article about estimate: Create an estimate.

As always, you can also reach out to our Customer Care support for additional help. They can use the screen share tool to get this resolved in no time.

Here's how you can reach them: 

1. Sign in to your QuickBooks Desktop company.
2. Select QuickBooks Desktop Help.
3. Click Contact us.

That should get you back on track.

Keep me posted if you have any other questions about adding a subtotal line item in your estimate or if you have any other questions about QuickBooks. I'll be happy to help you out. Wishing you and your business success.