Free UPC-A Retail Barcode Generator (GS1-US Modulo-10 Compliant)
Create verified 12-digit retail barcodes. Enter your 11-digit prefix to automatically compute the checksum digit. Download vector SVG, 600 DPI PNG, or print 30-up Avery sheets.
Loading UPC-A Barcode Generator...
Initializing GS1 Modulo-10 checksum validation & vector layout engine
Complete Engineering Guide to the Universal Product Code (UPC-A) and GS1 Checksum Mechanics
Step-by-step mathematical derivation of the Modulo-10 check digit and packaging magnification guidelines.
The Historical Origin and Global Architecture of UPC-A
Introduced in 1974 at a supermarket in Troy, Ohio to scan a 10-pack of Wrigley’s Juicy Fruit gum, the Universal Product Code (UPC-A) transformed retail inventory tracking and point-of-sale checkout worldwide. Governed globally by GS1, the UPC-A barcode encodes exactly 12 numeric decimal digits represented as a linear series of variable-width parallel bars and spaces.
The 12 digits are logically organized into three functional segments:
- Number System Character (Digit 1): Designates product category (e.g.
0, 1, 6, 7, 8for standard retail products;3for pharmaceuticals;2for variable-weight items like deli meats). - GS1 Company Prefix & Item Reference (Digits 2 through 11): Uniquely assigned by GS1 to identify the manufacturer brand, followed by the specific item SKU.
- Check Digit (Digit 12): A mathematical check character calculated via the Modulo-10 algorithm to catch manual typing and optical scanning errors.
Mathematical Step-by-Step Derivation of Modulo-10
Consider the 11-digit string 01234567890:
- Identify digits in odd positions (1st, 3rd, 5th, 7th, 9th, 11th):
0, 2, 4, 6, 8, 0. Sum =20. Multiply by 3:20 × 3 = 60. - Identify digits in even positions (2nd, 4th, 6th, 8th, 10th):
1, 3, 5, 7, 9. Sum =25. - Add both results:
60 + 25 = 85. - Divide 85 by 10. The remainder is
5. - Subtract remainder from 10:
10 - 5 = 5. The check digit is 5. The full 12-digit code is012345678905.
Avery 5160 Gang Print Sheet Specifications
Physical Metric Calibration Spec: Avery 5160 / 8160 Address Labels
72.0 pt/inch PostScript Engine| Layout Configuration | 3 Columns × 10 Rows (30 Labels per Sheet) |
|---|---|
| Label Dimensions | 2.625" × 1" (66.675 mm × 25.4 mm)[189pt × 72pt] |
| Sheet Page Size | 8.5" × 11" (215.9 mm × 279.4 mm) |
| Top & Left Margins | Top: 0.5" (12.7 mm) / Left: 0.1875" (4.762 mm) |
| Inter-Label Gaps | Horizontal: 0.125" (3.175 mm) / Vertical: 0" (0 mm) |
| Recommended Media | Mailing envelopes, barcode price tags, bin storage markers (LASER & INKJET) |
| Compatible Avery SKUs | 51608160526059606240652165256585846015660 |
Frequently Asked Questions: UPC-A Barcodes
Everything you need to know about physical margin calibration, print scale, and barcode readability.