I would like to create an invoice form that you can dynamically add items

Is there a way to generate an invoice with additional items on the fly?

For example, I'm looking for QTY, Description, Price. I'd like to be able to add items dynamically - much the same as the dynamic text box Widget. I would then want to calculate the totals with the calculated fields function if possible...

Unfortunately, we do not have a widget or a field that allows you to do this in the form. You may consider adding multiple fields, maybe up to 10 sets of fields then show the fields by conditional logic.

https://www.jotform.com/help/196-Hide-or-Show-Multiple-Fields-at-Once

You can use a number field to let users enter the number of quantity. The number field allows you to set a maximum number.

The calculation can be done with our calculation widget: https://www.jotform.com/help/259-How-to-perform-calculation-in-the-form. You can multiply the number field with the price per item. 

Let us know if you need further assistance.