Retail GTIN-13
EAN-13 Digits, Modulo-10 & Parity Encoding
How a GTIN-13 becomes an EAN-13 symbol: what each digit does, how the check digit is computed, how L/G/R parity hides the first digit in the left half, and what quiet zones mean at print time.
Generate EAN-13Digit anatomy (GTIN-13)
An EAN-13 carries thirteen decimal digits. The last digit is always a check digit. The first twelve are data you are authorized to use (company prefix + item reference in a variable split).
| Part | Typical role | Common mistake |
|---|---|---|
| GS1 prefix area | Points to the Member Organization that allocated the range | Treating it as "country of manufacture" |
| Company prefix | Identifies who may assign item references | Assuming every company prefix is six digits |
| Item reference | Distinguishes one trade item in that range | Reusing one GTIN across size/colour variants |
| Check digit | GS1 Modulo-10 error detection | Assuming a valid check proves ownership |
Seeing 400... does not mean the product was made in Germany.
Prefixes describe numbering administration, not the factory location on the packaging.
Modulo-10 worked example
Start with twelve data digits 400638133393. Counting from the right of those twelve,
weight odd positions x3 and even positions x1. The check digit makes the total sum a multiple of 10.
400638133393
89
1
4006381333931
In Qrivio you may paste twelve data digits or a full thirteen-digit number whose check already matches. A wrong thirteenth digit is rejected, not silently rewritten. The message shows the digit that belongs with that payload.
L / G / R parity
The printed bars are not twelve identical "digit fonts." EAN-13 uses three pattern families: L (odd parity left), G (even parity left), and R (right-hand). Digits 2-7 use a mix of L and G on the left half; digits 8-13 use R on the right half.
Quiet
Clear margin before the start guard.
Left half
Six digits; L vs G mix encodes digit 1 implicitly.
Right half
Six digits including the check, all R patterns.
Quiet
Clear margin after the stop guard.
The first digit is not drawn as its own separate bar cluster. Scanners recover it by recognising the L/G mix. That is also why a GTIN-13 that is a zero-padded GTIN-12 can interoperate with UPC-A at many POS lanes.
Sequential batches on Qrivio
When count is greater than one, Qrivio advances the payload before the check digit and recalculates Modulo-10. Do not treat the full thirteen-digit string as a plain integer.
Payload + recalc
4006381333931
4006381333948
4006381333955
Payload advances; check digit changes as required.
Integer bump of full GTIN
...3931
...3932
Leaves a wrong check digit. Qrivio will reject that full number later.
Quiet zones and magnification
Quiet zone Orientation aid often cited in packaging education: on the order of ~11 module widths left and ~7 right (near 0.33 mm module: roughly ~3.6 mm left, ~2.3 mm right). Use GS1 General Specifications and retailer manuals for production sign-off.
Magnification Undersizing for tiny packs invites no-reads. If the pack cannot hold a compliant EAN-13, ask about EAN-8 / GTIN-8 allocation -- do not crush thirteen-digit artwork.
Human-readable Digits under the bars help operators; the scanner reads the bars, not OCR of those digits.
Licence Drawing bars does not create a GS1 licence. Use numbers you are authorized to assign.