How can I create a form with calculation

I am a commercial printer and wondering how I can set up a form multiplier in URL example. Number of pages in file field that multiplies that number times other field number of sets to get a price.

That's possible using form calculation widget. Here's how to perform calculation in your form http://www.jotform.com/help/259-How-to-perform-calculation-in-the-form.

You can also perform calculation in the input table. Guide: https://www.jotform.com/help/343-How-to-Perform-Form-Calculation-in-the-Matrix-Field

If we can be of further help, let us know.