What is a UPC-A barcode?
A UPC-A barcode is the 12-digit retail barcode used across North America — the black-and-white code on almost every product sold in a US or Canadian store. In the GS1 standard it is called a GTIN-12 (Global Trade Item Number). You type 11 digits and this generator appends the 12th check digit automatically, then renders a clean, scannable barcode you can download as PNG, SVG or PDF. Everything runs in your browser with the bwip-js engine, so nothing you type is uploaded anywhere.
Need a different symbology? Use the full barcode generator for EAN-13, Code 128, GS1-128, ITF-14 and 17+ other types, or the dedicated QR code generator for URLs, Wi-Fi and vCards.
The 11 + 1 digit structure
A UPC-A is built from four parts. The first three make up the 11 digits you enter; the last is calculated for you:
| Part | Digits | What it means |
|---|---|---|
| Number system | 1 | Product category — 0 for most retail goods, 2 for weighed/random-weight items, 3 for drugs/health. |
| Company prefix | 6–10 | Your GS1-assigned manufacturer prefix — identifies the brand. |
| Item reference | 1–5 | The product number you assign inside your prefix. |
| Check digit | 1 | Calculated automatically here (see below) — you never type it. |
The company prefix and item reference together are always 10 digits, so a full UPC-A is 1 + 10 + 1 = 12 digits.
How the check digit works
The 12th digit is a modulo-10 check digit that lets a scanner catch a misread. From the first 11 digits: add the digits in the odd positions (1st, 3rd, 5th…) and multiply by 3, add the digits in the even positions, then take the number that brings the total up to the next multiple of 10. You don't need to do any of this by hand — enter 11 digits and the check digit appears automatically, and if you paste a full 12-digit code it is validated so you catch a typo before you print.
UPC vs EAN — which do I need?
They are the same family. UPC-A is the 12-digit code used in the United States and Canada; EAN-13 is the 13-digit code used in most of the rest of the world. A UPC-A is really an EAN-13 with a leading zero, and virtually all modern point-of-sale scanners read both. Rule of thumb: sell mainly into North American retail (or list on Amazon.com / Walmart) → use UPC-A; sell internationally → use EAN-13.
Where do UPC numbers come from?
A genuine, unique UPC is not something a generator invents — the number itself comes from GS1 (in the US, gs1us.org), which issues you a company prefix. You combine that prefix with your own item numbers to create a GTIN for each product. Amazon and Walmart require GS1-issued GTINs and cross-check them against the GS1 registry, so buying cheap resold "UPC codes" risks listing errors. This tool takes the number you already own and turns it into a correct, print-ready barcode image — it does not assign or sell UPC numbers.
How to generate a UPC-A barcode
- The UPC-A type is already selected for you above.
- Type your 11 digits in the data box (or paste all 12 to validate the check digit).
- Adjust size, quiet zone and colors — keep the quiet zone generous so retail scanners read it reliably.
- Download as PNG, SVG (best for print) or PDF.
Printing UPC labels reliably
Retail scanning is unforgiving, so a few basics matter. Keep the barcode at or near its nominal size (roughly 37 mm × 26 mm at 100%) — shrink it too far and the bars blur. Print in solid black on a white or light background, never light-on-dark, and leave the quiet zone (the blank margin on each side) intact. For crisp thermal output, download the SVG and let the printer render it at full resolution. To put the UPC on a real product label — with the price, product name and your logo — and print it directly to a thermal printer, use the free LabelInn app below.
Embed this UPC generator on your site
Free to embed — just keep the attribution link. Great for supplier portals, help centers and internal product-onboarding pages.
Frequently asked questions
Is this UPC barcode generator free?
Yes — no signup, no watermark, no limits. Everything runs in your browser, so nothing you type is uploaded.
How many digits is a UPC-A?
12 digits (a GTIN-12). You enter 11 and the 12th check digit is added for you.
Is the check digit calculated automatically?
Yes. Enter 11 digits and the modulo-10 check digit is computed; paste 12 and it is validated.
Where do I get a UPC number for Amazon or Walmart?
From GS1 (gs1us.org in the US), which issues your company prefix. This tool renders the barcode from a number you already own — it doesn't sell UPCs.
UPC or EAN?
UPC-A (12 digits) for North American retail; EAN-13 (13 digits) for international. Most scanners read both.
How do I print it to a Zebra or TSC printer?
Download the image, or use the free LabelInn app to place the UPC on a full label and print directly — including bulk runs from Excel.
Need other symbologies? Use the full barcode generator or the dedicated QR code generator. Designing full product labels? Try the free label maker, or explore all LabelInn features.