The Online Express form preview allows a quick look of the form's appearance. For this reason, the Goal Progress Bar does not calculate using the entered values. The bar will preview with a goal of $5000 and a total of $1500 received:

Donation form goal bar preview

To see the Goal Bar with the entered values, add the form's javascript code to a web page. Then view the published form on the web page in a browser. The entered values will appear on the live form.