Free UPC-A barcode generator

UPC-A at a glance

UPC-A is the barcode on products sold at checkouts in the United States and Canada. It carries one number, a 12-digit GTIN-12, and nothing else.

Sizes and quiet zones are from GS1’s symbol specification table 1 for products scanned at retail point of sale, in the GS1 General Specifications. GS1 treats the height and the width as one size: the minimum bar height is listed for the minimum, target and maximum X, and a symbol may be taller but never shorter.

A printed example

What each setting does for a UPC-A

• Data. Type 11 digits and the generator adds the check digit; type 12 and it checks the last one and tells you the right digit if yours is wrong. Spaces and dashes are ignored.
• X-dimension. Starts at 0.330 mm (100%). Outside GS1’s 0.264–0.660 mm range the generator warns you; the readout shows the magnification.
• Bar height. Starts at 22.85 mm. If you raise X without raising the height, the generator warns that the bars are truncated for that size.
• Quiet zone. 9 modules each side, GS1’s minimum. Less than that triggers a warning.
• Human-readable text. On by default. GS1 wants all 12 digits printed; turn it off only if your artwork sets the digits itself.
• Downloads. SVG comes out at the printed size in millimeters. PNG is made for a 203, 300 or 600 dpi printer with every module a whole number of dots.

Sizes that print cleanly

A label printer can only make bars a whole number of dots wide, so pick an X the printer can hit exactly. Counting a 203 dpi head as 8 dots per millimeter and a 300 dpi head as 12, as GS1 does:

Two dots at 203 dpi (0.250 mm, about 76%) falls below the usual 0.264 mm minimum. GS1 allows X from 0.249 mm up to 0.264 mm only for on-demand printing such as thermal or laser, and says the space set aside for the symbol and its quiet zones should never be smaller than a 0.264 mm symbol needs.

Common mistakes

• Making up the number. The generator draws any 12 digits with a valid check digit, but stores and marketplaces need a GTIN licensed to your company by GS1: GS1 US in the United States, or the GS1 office of your country. See how to get UPC barcodes.
• Cutting the bars short. GS1 US calls this truncation and warns it can cause incorrect scanning. Choose a smaller X with its matching height instead.
• Resizing the artwork. GS1 US says not to shrink or enlarge barcode art but to re-create it at the size you need. Change X here and download again.
• Red or patterned bars. GS1 US asks for dark bars in one ink on a light background, and warns that red bars are invisible to a scanner’s red light.
• Using a 13-digit number that starts with 0 as an EAN-13. It is the same GTIN; print the last 12 digits as a UPC-A. UPC vs EAN explains why both read the same.

Worked example: a UPC-A for a 300 dpi label printer

1. Type 61414112345. From the right, the digits are weighted 3, 1, 3, 1…: 5×3 + 4×1 + 3×3 + 2×1 + 1×3 + 1×1 + 4×3 + 1×1 + 4×3 + 1×1 + 6×3 = 78. The next multiple of ten is 80, so the check digit is 2 and the status line says 614141123452.
2. Keep X at 0.330 mm and the height at 22.85 mm. The readout shows 100% and a 37.3 mm wide symbol.
3. Choose 300 dpi. The PNG uses 4 dots per module, so X becomes 0.333 mm (101%) and the bars 23.08 mm: the height grows with X, so the symbol keeps its proportions.
4. Download the PNG, print it at 100% and scan a sample with the scanner your store uses.

The calculation is the one in section 7.9 of the General Specifications; the check digit calculator shows it step by step for any GS1 number.

Sources

1. GS1: GS1 General Specifications Standard (Release 26.0) (accessed October 27, 2026)
2. ISO: ISO/IEC 15420:2025, EAN/UPC bar code symbology specification (accessed October 27, 2026)
3. GS1 US: Barcode Placement & Printing Guidelines (accessed October 27, 2026)