Check Digit Calculator

What is my Check Digit?

The Check Digit is the last number encoded in a barcode symbol. It is calculated using the preceding digits and is used to validate the accuracy of the entire number.

GTIN Check Digit Calculator

ID Key Format	GTIN (without Check Digit)	Check Digit	GTIN (with Check Digit)
GTIN- 8*	(Enter 7 digits)
GTIN- 12	(Enter 11 digits)
GTIN-13	(Enter 12 digits)
GTIN-14	(Enter 13 digits)

* Note: the GTIN-8 field does not allow for check digits to be calculated for any numbers in an 8 digit format beginning with zero that have been allocated from GS1US. Please contact GS1 Philippines for further assistance.

Serial Shipping Container Code (SSCC)

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 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