GTIN Check Digit Calculator

How GTIN Check Digit Calculator Works?

The GTIN Check Digit Calculator works by detecting the payload length (7, 11, 12, or 13 digits), right-aligning the digits, and applying GS1 weights of 3 and 1 from the right. The tool then appends the check digit to produce a GTIN-8, GTIN-12, GTIN-13, or GTIN-14.

1. 1Select the GTIN length or let the tool detect it from the number of payload digits.
2. 2Right-align the payload: the last payload digit always gets weight 3.
3. 3Multiply digits by alternating weights 3 and 1 moving left.
4. 4Sum the products and compute (10 − (sum mod 10)) mod 10.
5. 5Append the check digit and pad to 14 digits with leading zeros when a GTIN-14 data format is required.

GTIN Check Digit Calculator Formula

The GTIN formula is Check Digit = (10 − (Σ dᵢ·wᵢ mod 10)) mod 10, with the same right-aligned weights for every GTIN length.

Right-align the payload, then:
S = Σ dᵢ × wᵢ,  wᵢ = 3 on the last payload digit, then 1, 3, 1… moving left
CD = (10 − (S mod 10)) mod 10   (same rule for GTIN-8, -12, -13, -14)

• d₁…d₁₂ are the 12 GTIN-13 payload digits (GS1 company prefix + item reference).
• d₁₃ is the GTIN-13 check digit.
• S is the weighted GTIN-13 sum.

5 × 3 = 15
4 × 1 = 4
3 × 3 = 9
2 × 1 = 2
1 × 3 = 3
4 × 1 = 4
3 × 3 = 9
2 × 1 = 2
1 × 3 = 3
0 × 1 = 0
9 × 3 = 27
5 × 1 = 5
S = 83
Check digit = (10 − (83 mod 10)) mod 10 = 7
GTIN-13 = 5901234123457
GTIN-14 data format = 05901234123457

GTIN Check Digit Calculator Conversion Table

The GTIN conversion table shows how each GTIN length converts to the 14-digit GTIN data format.

What is GTIN Check Digit Calculator?

A GTIN Check Digit Calculator is a tool that completes any Global Trade Item Number (GTIN) by computing its final GS1 check digit. GTINs identify trade items in retail, healthcare, and e-commerce across more than 100 countries.

GTINs come in 4 lengths: 8, 12, 13, and 14 digits. Right alignment lets all 4 lengths share one check digit rule, so a GTIN-12 padded to 14 digits keeps the same check digit.

What are the uses of GTIN Check Digit Calculator?

There are 4 main uses of the GTIN Check Digit Calculator, including barcode artwork, marketplace listings, and master data cleanup.

• Barcode artwork: Packaging designers complete GTINs before generating EAN or UPC symbols.
• Marketplace listings: Sellers confirm GTINs before uploading products to Amazon, Google Merchant Center, or eBay.
• Master data cleanup: Data teams find mistyped GTINs in product catalogues.
• Format conversion: Developers store every GTIN as 14 digits and keep the check digit valid.