pb de boucle

    Dim Somme As Double
    For colidx = 4 To 6
        For i = 3 To Rows.Count
            If Cells(i, 1) = "" or Cells(i,7)= 1 Then Exit For
             Somme = Somme + Sheets("feuil1").Cells(i + 1, colidx)
        Next i
    Next colidx
    MsgBox

Sub calc()
Dim derLig As Long 'Dernière ligne du tableau
Dim Col As Long, Lig As Long
Dim somme As Double
With Sheets("Feuil1") 'travailler sur la feuille Feuil1
    derLig = .Cells(Rows.Count, 1).End(xlUp).Row
    For Col = 4 To 6
        For Lig = derLig To 3 Step -1
            If .Cells(Lig, 7) = 1 Then
                .Cells(Lig, Col) = somme
                somme = 0
            Else
            somme = somme + .Cells(Lig, Col)
            End If
        Next
    Next
End With
End Sub