EAN-13 Barcode Explained: Format, Check Digit and Minimum Size

Turn over almost any packet in a Malaysian supermarket and you'll find an EAN-13: 13 digits under a block of black bars. It's the barcode shops scan at the till. Here's what the numbers mean, how the last digit is worked out, and how big to print it so it scans first time.

What EAN-13 is

EAN-13 is the standard retail barcode used across most of the world. EAN stood for European Article Number; today the system is run by GS1, and the 13-digit number is called a GTIN-13 (Global Trade Item Number). North America uses the 12-digit UPC-A, which is the same system with one digit fewer, so tills everywhere read both.

What the 13 digits mean

GS1 prefix (first 3 digits). Shows which GS1 office issued the number. GS1 Malaysia's prefix is 955. It tells you where the number was issued, not where the product was made.
Company number. The digits after the prefix that identify your company. Together with the prefix this is your GS1 Company Prefix. Its length depends on how many products your licence covers.
Product number. The digits you choose for each product, flavour and pack size.
Check digit (last digit). Calculated from the other 12, so a scanner can tell if it misread a bar.

The numbers must come from GS1 for shops to accept them. If you don't have yours yet, see how to get a barcode in Malaysia.

How to work out the check digit

Take the first 12 digits. Multiply them, from the left, by 1, 3, 1, 3 and so on. Add up the results. The check digit is whatever you need to add to reach the next multiple of 10 (if the total already ends in 0, the check digit is 0).

Worked example with the first 12 digits 4 0 0 6 3 8 1 3 3 3 9 3:

Times 1, 3, 1, 3...: 4, 0, 0, 18, 3, 24, 1, 9, 3, 9, 9, 9
Total: 89
Next multiple of 10 is 90, so the check digit is 1.
Full number: 4006381333931

You don't have to do this by hand. In the free barcode generator, pick EAN-13 and type the first 12 digits: it adds the check digit for you. If you type all 13 and the last one is wrong, it tells you.

How big to print it

Size is where most home-made barcodes go wrong. The GS1 specifications set the EAN-13 standard size, called 100% magnification:

Standard size (100%): about 37.29 mm wide by 25.93 mm high, including the white margins and the numbers.
Allowed range: 80% to 200% of that, so from about 29.83 x 20.74 mm up to about 74.58 x 51.86 mm.
Narrowest bar (the "X-dimension"): 0.33 mm at 100%.
White margins (quiet zones): 11 times the narrowest bar on the left and 7 times on the right; about 3.63 mm and 2.31 mm at 100%.

Two rules matter more than the exact number. Scale it evenly: make the whole barcode bigger or smaller, never squash or stretch it one way. And don't cut the height: designers often trim the bars to save space, which GS1 advises against because shorter bars are harder to scan. Printers can also make bars spread, so smaller than 100% needs a good printer. If in doubt, stay at 100% or larger. Check the latest GS1 General Specifications or ask GS1 Malaysia if a retailer needs an exact size.

Printing tips

Dark bars on a light background. Black on white is best. Red, orange or yellow bars, or bars on a dark or metallic background, often won't scan.
Download as SVG for print. SVG is made of shapes, so it stays sharp at any size. Use PNG for screens and quick labels, at a high resolution.
Keep it flat. Away from folds, seals, curves and the edge of a can.
Check the proof. Scan the printed proof before the full run. GS1 Malaysia offers paid barcode certification if a retailer wants proof.

EAN-13 vs EAN-8 vs UPC

EAN-8 is a shorter 8-digit code for very small packs where an EAN-13 won't fit; GS1 issues these separately. UPC-A is the 12-digit North American version, and UPC-E a compressed one for small packs. Not sure if you need a barcode or a QR code at all? Read barcode vs QR code.

Make an EAN-13 barcode →

Questions

What do the numbers on an EAN-13 barcode mean?

The first 3 digits are the GS1 prefix of the issuing country office, then your company number, then the product number, and the last digit is a check digit.

How do you calculate the EAN-13 check digit?

Multiply the first 12 digits by 1, 3, 1, 3 and so on from the left, add them up, and the check digit is what brings the total to the next multiple of 10.

What is the minimum size of an EAN-13 barcode?

Under the GS1 specifications, 80% of the standard size: about 29.83 x 20.74 mm. Smaller than 100% needs good printing; 100% or larger is safer.

Does 955 mean the product was made in Malaysia?

No. 955 means the number was issued by GS1 Malaysia, not where the product was made.

What is the difference between EAN-13 and UPC?

UPC-A is the 12-digit North American version of the same system. Tills around the world read both.