QR code size for a name badge

Make badge QR codes at least 3 cm, ideally 4–5 cm on a 10 × 7.5 cm badge. Conversation distance would demand an impossible 5–10 cm code, but people naturally hold a badge out at 20–30 cm to be scanned. Print the code on both sides: lanyard badges spin.

Which distance are you designing for?

Interaction	Distance	10:1 width	Fits a badge?
Read mid-conversation, hands down	50–100 cm	5–10 cm	barely, or not
Badge held out to be scanned	20–30 cm	2–3 cm	yes
Badge on the chest, scanner leans in	40 cm	4 cm	yes

The honest answer is that you cannot size for passive conversation distance, a 10 cm code would be the badge. Fortunately you do not need to: scanning a badge is a cooperative act, and the wearer holds it out. Design for the held-out badge: 3 cm floor, 4–5 cm target. The 4 cm figure also covers the lean-in case, which is how badge scanning actually happens at trade shows and conferences.

The real-estate fight

A typical badge is 10 × 7.5 cm (or credit-card sized at 8.6 × 5.4 cm), and its first job is the wearer's name in large type. On the 10 × 7.5 format, a 4 cm code plus quiet zone takes about a quarter of the face, workable if the code sits in a lower corner. On credit-card badges, 3 cm is the realistic ceiling, which in turn caps the payload: keep it to a short profile URL (version 2–3) rather than a full vCard, whose density needs more width than the badge has, the same arithmetic as a business card.

The lanyard flip

The badge-specific failure has nothing to do with printing: badges on single-clip lanyards spin, and at any moment roughly half the badges in a hall face backwards. A perfect code on the front of a flipped badge scans exactly never.

Fixes, in order of robustness:

Print the code on both sides. Duplex badge stock costs pennies more and makes orientation irrelevant.
Double clips or badge holders that cannot rotate.
At minimum, put the code on the back as well as the front of the insert if holders are single-sided pouches: the pouch shows both.

Error correction and finish

EC M, badges live for a day or three and rarely take damage worth 25% redundancy; spending the density on a bigger module wins. Choose matt laminate or matt pouches: exhibition halls are lit by high, bright point sources, and gloss pouches produce the same hotspot problem as laminated menus. Size-check the payload with the size calculator and verify the artwork decodes before the badge run, 500 badges with a typo'd URL is a bad first morning. The surface details live on the name badges page.

FAQ

What size should a QR code be on a name badge?

At least 3 cm, ideally 4–5 cm on a 10 × 7.5 cm badge. Badges are scanned held out at 20–30 cm rather than read at conversation distance, which is what makes those sizes workable.

Should the QR code go on the front or back of a badge?

Both. Lanyard badges spin, so half face backwards at any moment. Printing the same code on both sides (or both faces of the insert in a clear pouch) makes the flip irrelevant.

Should a badge QR code be a vCard or a URL?

A short URL to a profile page, in most cases. Badge space caps the code at 3–4 cm, and a full vCard's density wants more width than that. A lean vCard works if offline contact exchange is essential.

What error correction level should badge codes use?

M. Badges are short-lived and lightly handled, so heavy redundancy buys little; keeping the version low and the modules large helps more, especially on credit-card-sized badges.