UPC & EAN check digit calculator
Enter an 11-digit UPC or 12-digit EAN prefix—or paste a full 12/13-digit barcode—to verify the GS1 Modulo-10 check digit and download a scan-ready sticker.
One sticker free · batches saved from $9
03600029145
Paper: 2.625 × 1 in (Avery 5160)
How the GS1 Modulo-10 check digit algorithm works
From a single product code or an Excel spreadsheet to scan-ready stickers in three steps.
Step 1
Paste a product line or upload CSV
Enter one UPC, EAN, or Amazon X00 FNSKU code above, or upload a spreadsheet with hundreds of SKUs and quantities.
Step 2
Auto-verify check digits & quiet zones
We calculate the 12th Modulo-10 check digit and lock GS1 quiet-zone margins automatically—no pixel sliders to mess up.
Step 3
Download single PNG/SVG or 30-up PDF
Export a single sticker for free, or generate a server-calibrated Avery 5160 30-up US Letter sheet or 2" × 1" thermal roll PDF.
Row 7 036000291450 036000291452 recomputed before printing
Verify & auto-repair check digits across an entire CSV spreadsheet
Restock runs are either a single product going out in one carton, or a whole catalogue at once. Both land on the same calibrated sheet: 30 identical labels, or a mixed page filled row by row from your CSV.
Clone one code across the page. A full carton of the same item: enter the FNSKU or UPC once, choose 30, and our server PDF engine returns a US Letter PDF with all 30 cells filled.
A CSV with quantities per SKU. Upload the list from your ERP — A needs 10, B needs 20 — and it is paginated, mixed and filled in order. UPC-12, EAN-13, FNSKU and GTIN-14 rows can share a sheet.
Every check digit recomputed first. A wrong Modulo-10 digit is corrected before layout and flagged in the row, so a bad code never reaches a warehouse scanner.
Archived in your cloud Saved Batches. Reopen your batch on a phone or a different laptop at the next restock and download the exact PDF from cloud storage—no re-upload, no re-typing.
Built for the physical print, not a generic graphic
215.9× 279.4 mm
True US Letter (612 × 792 pt). When generic generators export A4 onto US Letter sheets, the bottom rows drift off the perforation.
30/ 30 codes
Every Modulo-10 check digit and Code 128A checksum is verified on the server before your PDF is written.
Cloudsaved batches
Signed in, every PDF sheet you generate is stored in Cloudflare R2 with its verified SKU rows for instant one-click reprints.
Modulo-10 step-by-step calculation reference
The four barcode standards required by US retail checkout lanes and Amazon FBA fulfillment centers—and the exact physical tolerances locked into our engine.
| Code Standard | Structure | Where It Is Required | Mandatory Compliance Rule |
|---|---|---|---|
| UPC-A | 12 digits (11 + check) | US & Canadian retail POS, Amazon listings using manufacturer barcodes | Nominal 37.29 × 25.91 mm at 100% (X = 0.330 mm); left/right quiet zones ≥ 9X (2.97 mm) |
| Amazon FNSKU | 10 chars, starts X00 | Every private-label or non-commingled unit shipped to Amazon FBA | Code 128A bars with ≥ 0.25 in side quiet zones, X00 string under bars, title, and raw condition (e.g. New); no retail price |
| EAN-13 | 13 digits (12 + check) | International / European retail and global GTIN-13 catalogues | Left quiet zone ≥ 11X (3.63 mm), right ≥ 7X (2.31 mm); leading system digit outside left guard bar |
| GS1 DataMatrix | (01) GTIN-14 + (17) + (10) | Medical devices, pharmaceuticals, cosmetics, and logistics cartons | FNC1 prefix + Application Identifiers in fixed order with ≥ 1X white border on all 4 sides |
Verified October 2026 against GS1 US General Specifications Section 5.2 and Amazon Seller Central FBA Item Label Specification G200141490.
Explore more barcode & label tools
Dedicated generators pre-configured for specific barcode standards, label sheets, and thermal rolls.
Check digit calculator FAQ
What happens if I paste a 12-digit UPC with the wrong last digit?
Our studio compares the 12th digit you pasted against the true Modulo-10 check digit of the first 11 digits, flags the mismatch immediately, and corrects it so you never print an unscannable barcode.
Start with 3 free sheet credits.
Single PNG & SVG stickers are always free. Create a free account to get 3 sheet credits for 30-up Avery 5160 PDFs and cloud Saved Batches.