You'll probably be better off doing these calculations in your data source, rather than in the grid. That way, the calculations will remain consistent regardless of how you sort or group the grid.If you were modifying values in the current row, rather than in subsequent rows, you might be able to leverage the ListIndex property of the UltraGridRow object. This represents the index of the data item which the row represents, which remains unchanged when the grid is sorted or grouped. There's a "GetRowAtListIndex()" method on the RowsCollection object, but this becomes excessively difficult to implement in conjunction with grouping (since this moves rows to new rows collections).Please remember that these forums area a peer-to-peer resource to share issues and ideas with other Infragistics users. If you require official support from Infragistics, please submit a support request to Infragistics Developer Support from this page of our website.