Text Form Field Expression - Calculate Average but Ignore '0' or 'N/A'

Try this:

Sub CalculateAverage()
    Dim ADP As Double
    Dim Fit As Double
    Dim TimeAway As Double
    Dim Calendar As Double
    Dim Sum As Double
    Dim Count As Integer

    ' Assign values from form fields
    ADP = CDbl(ActiveDocument.FormFields("ADP").Result)
    Fit = CDbl(ActiveDocument.FormFields("Fit").Result)
    TimeAway = CDbl(ActiveDocument.FormFields("TimeAway").Result)
    Calendar = CDbl(ActiveDocument.FormFields("Calendar").Result)

    ' Initialize sum and count
    Sum = 0
    Count = 0

    ' Check each value and add to sum if it's valid
    If ADP > 0 Then
        Sum = Sum + ADP
        Count = Count + 1
    End If
    If Fit > 0 Then
        Sum = Sum + Fit
        Count = Count + 1
    End If
    If TimeAway > 0 Then
        Sum = Sum + TimeAway
        Count = Count + 1
    End If
    If Calendar > 0 Then
        Sum = Sum + Calendar
        Count = Count + 1
    End If

    ' Calculate average
    If Count > 0 Then
        ActiveDocument.FormFields("Average").Result = Format(Sum / Count, "0.00")
    Else
        ActiveDocument.FormFields("Average").Result = "N/A"
    End If
End Sub