What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Depending on what you are looking for.
In your calculation, this is how it should work:
freight + (subtotal * 8.25%) = total.
Here's a sample form: http://form.jotformpro.com/form/52090720458958?
Here's how my form calculation widget is set:
I also checked your form and it seems to work as expected:
Let us know if the calculation is still incorrect and please provide us more details of it.