How do I to create a two series pie chart that compares this record's value to the total value of all other active records in the table.

I have a table that contains Name, numeric value and active status.  When I pull up one of the individual records, I would like to create a two series pie chart that compares this record's value to the total value of all other active records in the table.  I'm assuming I need to create a  formula field, but not sure how to capture the sum for the entire table's active records' values.