You can view the finished size of your product as you are creating your product in Customise your Frame. You can also view the finished product size at the checkout page.
In Customise your Frame
Select your moulding. In the description box below your selected moulding you will be able to see the vertical and horizontal increase in size this moulding will apply to the finished product.
At the Checkout page
The finished size displayed includes the print size and the selected moulding.