Hi P-E,

First, built an Access total query type with an average field. Pull down all needed fields to be displayed on the DBGrid.

Second, associate the query to the Datasource and then associate the DBGrid to the datasource. There you will have bounded fields of the DBGrid to the table, except for the last field which is the average field.

Last, the DBGrid has a module property called "DBGrid1_AfterUpdate"

Private Sub DBGrid1_AfterUpdate()
me!DSAverage.refresh
End Sub

or you can validate whenever the current cell has been modified

if Me!DBGrid1.CurrentCellModified then
me!DSAverage.refresh
end if


HTH