Create a customized total field before the Shipping Cost. (Subtotal + Tax Total - Discount total)

To create a customized total field on the Sales Order Form where the Shipping cost is not included (Subtotal + Tax Total - Discount total), follow the steps below:

1. Navigate to Setup > Customization > Transaction Body Fields > New
2. Enter a Label
3. Type= Currency
4. Store Value= unchecked
5. Navigate to the Applies To subtab and mark Sale =T
6. On the Display Subtab, set Subtab= Main
7. Under Validation & Defaulting subtab > Default Value= (({subtotal}+{taxtotal})-{discounttotal}) and Formula = T
8. Click Save & Apply To Forms

Note: Make sure that you apply the changes to the form which you needed the field to show up.