A retail barcode (UPC-A or EAN-13) is about 37 mm wide at its standard size, and you can print it anywhere from 80% to 200% of that. Label barcodes like Code 128 have no fixed size: keep the narrowest bar at least 0.19 mm wide, and wider for scanning at a distance. Whatever the type, keep the blank margins, use dark bars on a light background, and send your printer a file that keeps every bar sharp.
Retail barcodes: the standard sizes
| Type | Width at 100% with margins | Allowed range |
|---|---|---|
| UPC-A | 37.3 mm | 80% to 200% (about 30 to 75 mm) |
| EAN-13 | 37.3 mm | 80% to 200% |
| EAN-8 | 26.7 mm | 80% to 200% |
| UPC-E | 22.1 mm | 80% to 200% |
| ITF-14 | About 152 mm with bearer bars | About 50% to 100%, depending on the print method |
Our generator starts each retail type at 100% and tells you the size as you change it. Bigger is easier to scan; going below 80% is the most common reason a retail barcode fails at the till.
Label barcodes: bar width matters
For Code 128, Code 39 and GS1-128, the size comes from the narrowest bar (the X-dimension) and how much data you encode.
- 0.19 mm: the practical minimum, for close-range scanning on good printers.
- 0.25 to 0.33 mm: a safe choice for most labels.
- 0.5 mm and up: for warehouse labels scanned from a distance.
The generator shows the narrowest bar as you resize and warns when it gets too thin. To make a long code narrower, shorten the data rather than shrinking the bars.
For 2D codes (Data Matrix, Aztec, PDF417), the same idea applies to each square: 0.25 mm is a sensible minimum for scanners, more for phones.
Margins: don’t trim them
Every barcode needs blank space on both sides, called the quiet zone. Scanners use it to find where the code starts and ends. A UPC-A needs about 9 bar widths on each side; Code 128 needs at least 10. Our downloads include the margins: don’t crop them, and don’t let a box edge, text or a design element run into them.
Colours and backgrounds
- Dark bars, light background. Black on white is best. Dark blue, green or brown on white, cream or light grey also work.
- Avoid red, orange and yellow bars. Many scanners use red light, so red bars look like background.
- No reversed barcodes. Light bars on a dark background fail on many scanners.
- Transparent backgrounds are fine only if what’s behind is plain and light.
Which file to send your printer
- PNG at the final size: for office printers, labels and most digital printing. Every bar is a whole number of pixels, so widths stay exact. Don’t resize it afterwards.
- SVG, PDF or EPS: for packaging and print shops. Vector files stay sharp at any size and let the printer adjust bar width for ink spread. These come with a paid plan.
- Thermal printers: print at 100% at the printer’s own resolution; resized images print uneven bars. Zebra users can use ZPL.
Before the print run
- Print one proof at the final size on the real material.
- Scan it with the kind of scanner that will read it: a till, a warehouse gun or a phone app.
- Check the number it reads matches your records.
- Look at curved or shiny surfaces: bars running around a bottle should run up and down, not around.