# 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

ID Key Format
Item Reference
(without Check Digit)

Check
Digit
GTIN-8
(Enter 7 digits)
GTIN-12
(Enter 11 digits)
GTIN-13
(Enter 12 digits)
GTIN-14
(Enter 13 digits)

## GLN Check Digit Calculator

ID Key Format
Item Reference
(without Check Digit)

Check
Digit
Global Location Number (GLN)
GLN
(Enter 12 digits)

## SSCC Check Digit Calculator

ID Key Format
Item Reference
(without Check Digit)

Check
Digit
SSCC
(Enter 17 digits)

## 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

-

=

=

=

=

=

=

=

=

=

=

=

=

-

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