Currently, the Pivot chart has a "grand total" bottom row that adds the values in the chart. However, I need this row to perform a different calculation. Specifically, I'm building a multi-dimensional income statement which need to subtract expenses from revenue to show the resulting income. I've tried different ways modifying the underlying data, but currently nothing works. Customisable (formula) rows would add great versatility to the pivot chart and should be an easy fix. Please work on it.