Application.CalculationState (Excel)
Returns an XlCalculationState constant that indicates the calculation state of the application, for any calculations that are being performed in Microsoft Excel. Possible return values are xlCalculating - Calculations in process, xlDone - Calculations complete, xlPending - Changes that trigger calculation have been made, but a recalculation has not yet been performed.
If Application.CalculationState = xlDone Then
MsgBox "Done"
Else
MsgBox "Not Done"
End If