Check digit calculator

The last digit of a barcode number is a computer check digit which makes sure the barcode is correctly composed. Use our check digit calculator below to calculate a check digit.

Calculate a check digit

What is a check digit?

The last digit of all fixed-length, numeric GS1 Identification Keys is a check digit that ensures the integrity of the key.
All GS1 ID Keys need a check digit, except Component/Part Identifier (CPID) and Global Individual Asset Identifier (GIAI). Global Model Number (GMN) includes a pair of check characters rather than a single check digit.


How does the check digit calculator work?

The check digit is calculated using a simple algorithm, based on the other numbers in the key.
Find out how to calculate a check digit manually.

Find out more

Easy use of GS1 standards with digital services and smart online tools.

The GS1 General Specifications

This document describes how GS1 barcodes and identification keys should be used.

Access the GS1 General Specifications 19.0

GS1 identification keys

GS1 ID Keys give companies efficient ways to access information about items in their supply chains, and share this information with trading partners.

View the list of keys

Who owns this barcode?

You can know about the owner of a barcode thanks to our tool.

Check who owns a barcode