The New Calculated Fields Window

You can create new fields or measures in an Ad Hoc view by applying formulas to a view's existing fields and measures.

For example, consider a view that includes both a "Cost" and a "Revenue" field. You could calculate the profit for each record by creating a custom "Profit" field that subtracts the "Cost" field from the "Revenue" field. You could also then divide the "Profit" custom field by the "Revenue" field to express each record's margin as a percent.