What this UPC code generator does
The UPC barcode generator draws the barcode for a UPC number you already own. It does not issue numbers. To sell in US and Canadian shops, and on most marketplaces, your UPC needs to come from GS1 US, which licenses either single numbers or a company prefix that lets you create your own range.
Once you have the number, the generator handles the fiddly part: the check digit, the bar pattern and the human-readable digits under the bars, all to the UPC specification.
UPC-A vs UPC-E
UPC-A is the standard 12-digit code you see on most North American products. The digits hold your GS1 company prefix, your product number and a final check digit. Its full size is about 37 mm wide.
UPC-E is a compressed 8-digit version for very small packs, such as cans of soda or cosmetics. It works by squeezing out runs of zeros, so only some UPC-A numbers can be shortened. If your number has no suitable zeros, you must use UPC-A.
How the UPC check digit works
The 12th digit catches mistakes. Add up the digits in the odd positions and multiply by three, then add the digits in the even positions. The check digit is whatever brings the total up to the next multiple of ten. For 03600029145, that gives 2, so the full code is 036000291452. You never need to do this by hand; type 11 digits and the generator fills in the last one.
How to create a UPC barcode that prints and scans
- Choose UPC-A, or UPC-E for a small pack, in the generator.
- Enter the 11 digits from GS1 US. The check digit is added and the barcode updates.
- Download SVG. It is vector, so it stays sharp at any size in your packaging artwork.
- Place it at nominal size, 37.29 mm by 25.91 mm, or anywhere between 80% and 200% of that.
- Keep a clear quiet zone of white space either side of the bars, and print a test copy to scan before a full run.
Common UPC printing mistakes
Most failed UPC labels come down to a few habits. Placing the barcode over a seam, fold or curved edge distorts the bars. Printing on clear film without a white box behind it leaves the scanner nothing to contrast against. Rescaling a PNG in a design tool blurs the bar edges; use the SVG instead. And putting two different UPCs on the same pack confuses tills, so cover any old code completely.
Size, quiet zones and colour
- Magnification: 80% to 200% of nominal. Below 80% many till scanners struggle.
- Height: do not trim the bars shorter to save space. Truncated UPCs often fail at the till.
- Quiet zone: leave at least nine bar widths of blank space on the left and right. Keep text and borders out of it.
- Colour: dark bars on a light background. Black on white is safest; red bars do not scan because scanners use red light.
