• The first digit is not coded but it determines the tables to be used for coding the following 6 digits.
• The width of a thin bar (0.33 mm standard) is called the module.
• There are bars of 1, 2, 3 or 4 modules; the same applies to spaces.
• Each number is coded on 7 modules, each comprising 2 bars and two spaces.

• The start and end markers are : «101»
• The separator mark placed in the middle after the 7th digit is : «01010»
• The total length is always 12 * 7 + 2 * 3 + 5 = 95 modules ; there are always 30 bars in total.
• The separator bars are 5 modules longer than the other bars.
• You need white margins of at least 11 modules on the left and 7 modules on the right.

• The graphic method where each bar is "drawn" as a full rectangle. This method enable to compute the width of each bar with a one pixel precision and so we can work with widths which are perfect multiple of the used device pixel. This give us a good accuracy specially if the device have a low density as it's the case with screens and inkjet printers. This method require special programming routines and does not allow to make bar codes with a current software.
• The special font in which each character is replaced by a barcode. This method allow the use of any software like a text processing or a spreadsheet. (For example LibreOffice, the free clone of MSoffice !) The scale settings according to the selected size can bring away small misshaping of the bar drawing. With a laser printer there's no probs.

• Table A : Set of code A with the digit under the barcode.
• Table B : Set of code B with the digit under the barcode.
• Table C : Set of code C with the digit under the barcode.
• Table D : Set of digits with the start delimiter
• Table E : Set of digits without the start delimiter (Requested for the SAGE softwares)

Copy this file in the font directory, often named : : \Windows\Fonts

• Digit number 1 from table D (Left quiet zone and start delimiter included)
• 6 digits from tables A or B according to the first digit
• Middle delimiter
• 6 digits from table C
• End delimiter (Right quiet zone included)

Here is a small program written with Visual Basic 6.
The setup file copy the program, Visual Basic
dependencies, source files and the font.

Setup file :

ZIP file without setup :

Public Function ean13$(chaine$)
  'Cette fonction est régie par la Licence Générale Publique Amoindrie GNU (GNU LGPL)
  'This function is governed by the GNU Lesser General Public License (GNU LGPL)
  'V 1.1.1
  'Paramètres : une chaine de 12 chiffres
  'Parameters : a 12 digits length string
  'Retour : * une chaine qui, affichée avec la police EAN13.TTF, donne le code barre
  ' * une chaine vide si paramètre fourni incorrect
  'Return : * a string which give the bar code when it is dispayed with EAN13.TTF font
  ' * an empty string if the supplied parameter is no good
  Dim i%, checksum%, first%, CodeBarre$, tableA As Boolean
  ean13$ = ""
  'Vérifier qu'il y a 12 caractères
  'Check for 12 characters
  If Len(chaine$) = 12 Then
    'Et que ce sont bien des chiffres
    'And they are really digits
    For i% = 1 To 12
      If Asc(Mid$(chaine$, i%, 1)) < 48 Or Asc(Mid$(chaine$, i%, 1)) > 57 Then
i% = 0
Exit For
      End If
    Next
    If i% = 13 Then
      'Calcul de la clé de contrôle
      'Calculation of the checksum
      For i% = 12 To 1 Step -2
checksum% = checksum% + Val(Mid$(chaine$, i%, 1))
      Next
      checksum% = checksum% * 3
      For i% = 11 To 1 Step -2
checksum% = checksum% + Val(Mid$(chaine$, i%, 1))
      Next
      chaine$ = chaine$ & (10 - checksum% Mod 10) Mod 10
      'Le premier chiffre est pris tel quel, le deuxième vient de la table A
      'The first digit is taken just as it is, the second one come from table A
      CodeBarre$ = Left$(chaine$, 1) & Chr$(65 + Val(Mid$(chaine$, 2, 1)))
      first% = Val(Left$(chaine$, 1))
      For i% = 3 To 7
tableA = False
 Select Case i%
 Case 3
   Select Case first%
   Case 0 To 3
     tableA = True
   End Select
 Case 4
   Select Case first%
   Case 0, 4, 7, 8
     tableA = True
   End Select
 Case 5
   Select Case first%
   Case 0, 1, 4, 5, 9
     tableA = True
   End Select
 Case 6
   Select Case first%
   Case 0, 2, 5, 6, 7
     tableA = True
   End Select
 Case 7
   Select Case first%
   Case 0, 3, 6, 8, 9
     tableA = True
   End Select
 End Select
       If tableA Then
 CodeBarre$ = CodeBarre$ & Chr$(65 + Val(Mid$(chaine$, i%, 1)))
       Else
 CodeBarre$ = CodeBarre$ & Chr$(75 + Val(Mid$(chaine$, i%, 1)))
       End If
     Next
      CodeBarre$ = CodeBarre$ & "*"   'Ajout séparateur central / Add middle separator
      For i% = 8 To 13
CodeBarre$ = CodeBarre$ & Chr$(97 + Val(Mid$(chaine$, i%, 1)))
      Next
      CodeBarre$ = CodeBarre$ & "+"   'Ajout de la marque de fin / Add end mark
      ean13$ = CodeBarre$
    End If
  End If
End Function
			

Demo Excel file

File for Libre Office

Language Author   Neobook 4 Jean-Louis HUVE Visual Foxpro Emile MAITREJEAN Delphi John SWIJSEN Delphi YARDIMLI EKIM Delphi Francisco FERNANDEZ C# Russell SAYERS Perl Simone FIORAVANTI Axapta Søe JESPER

The EAN 8 code

Public Function EAN8$(chaine$)
  'V 1.0.0
  'Paramètres : une chaine de 7 chiffres
  'Parameters : a 7 digits length string
  'Retour : * une chaine qui, affichée avec la police EAN13.TTF, donne le code barre
  ' * une chaine vide si paramètre fourni incorrect
  'Return : * a string which give the bar code when it is dispayed with EAN13.TTF font
  ' * an empty string if the supplied parameter is no good
  Dim i%, checksum%, first%, CodeBarre$, tableA As Boolean
  EAN8$ = ""
  'Vérifier qu'il y a 7 caractères
  'Check for 7 characters
  If Len(chaine$) = 7 Then
    'Et que ce sont bien des chiffres
    'And they are really digits
    For i% = 1 To 7
      If Asc(Mid$(chaine$, i%, 1)) < 48 Or Asc(Mid$(chaine$, i%, 1)) > 57 Then
i% = 0
Exit For
      End If
    Next
    If i% = 8 Then
      'Calcul de la clé de contrôle
      'Calculation of the checksum
      For i% = 7 To 1 Step -2
checksum% = checksum% + Val(Mid$(chaine$, i%, 1))
      Next
      checksum% = checksum% * 3
      For i% = 6 To 1 Step -2
checksum% = checksum% + Val(Mid$(chaine$, i%, 1))
      Next
      chaine$ = chaine$ & (10 - checksum% Mod 10) Mod 10
      'Les 4 premier chiffre viennent de la table A
      'The first 4 digits come from table A
      CodeBarre$ = ""   'Ajout marque de début / Add start mark
      For i% = 1 To 4
 CodeBarre$ = CodeBarre$ & Chr$(65 + Val(Mid$(chaine$, i%, 1)))
      Next
      CodeBarre$ = CodeBarre$ & "*"   'Ajout séparateur central / Add middle separator
      For i% = 5 To 8
CodeBarre$ = CodeBarre$ & Chr$(97 + Val(Mid$(chaine$, i%, 1)))
      Next
      CodeBarre$ = CodeBarre$ & "+"   'Ajout de la marque de fin / Add end mark
      EAN8$ = CodeBarre$
    End If
  End If
End Function