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Check Digit Calculator

The last digit of a bar code number is a computer Check Digit which makes sure the bar code is correctly composed.
This page contains the following information:
  • GTIN Check Digit Calculator
  • SSCC Check Digit Calculator
  • How to calculate a Check Digit manually

GTIN Check Digit Calculator
Item Reference Number:
(without Check Digit)
SSCC Check Digit Calculator
Item Reference Number:
(without Check Digit)

How to calculate a Check Digit manually

ID Key Format Digit Positions
GTIN-8 N1 N2 N3 N4 N5 N6 N7 N8
GTIN-12 N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12
GTIN-13 N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12 N13
GTIN-14 N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12 N13 N14
SSCC N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12 N13 N14 N15 N16 N17 N18
Step 1: Multiply value of each position by
x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3 x1 x3
Step 2: Add results together to create sum
Step 3: Subtract the sum from nearest equal or higher multiple of ten = Check Digit

The following table gives an example to illustrate how a GTIN-13 Check Digit is calculated:
Positions N1 N2 N3 N4 N5 N6 N7 N8 N9 N10 N11 N12 N13
Number without Check Digit 6 2 9 1 0 4 1 5 0 0 2 1 -
Step 1: Multiply x x x x x x x x x x x x -
by 1 3 1 3 1 3 1 3 1 3 1 3 -
Step 2: Add results = = = = = = = = = = = = -
to create sum 6 6 9 3 0 12 1 15 0 0 2 3 =57
Step 3: Subtract the sum from nearest equal or higher multiple of ten = 60- 57 = 3 (Check Digit)
Number with Check Digit 6 2 9 1 0 4 1 5 0 0 2 1 3