Yes, you can add a pie chart. Your best bet for adding an interactive chart that changes automatically when the calculator numbers change is ChartJS. https://www.chartjs.org/. It happens that one of the top ChartJS experts is listed in the Formidable Masterminds Developers Directory: https://formidable-masterminds.com/developer/nick/. Nicky Wong is new to Formidable. If you can feed him the numbers, he can create a beautiful chart for you.