@Shay A - 'google tells this' http://www.contextures.com/excel-pivot-table-calculated-field.html
Features
- For calculated fields, the individual amounts in the other fields are summed, and then the calculation is performed on the total amount.
- Calculated fields are automatically available in all pivot tables that are based on the same pivot cache
Limitations
- Calculated field formulas cannot refer to the pivot table totals or subtotals
- Calculated field formulas cannot refer to worksheet cells by address or by name.
- Sum is the only function available for a calculated field.
- Calculated fields are not available in an OLAP-based pivot table.