Here's a formula to get the best size for your QR codes:
Scanning Distance / 10 = Minimum QR Code Size (as long as this number is not lower than 0.4" (1cm)).
For instance, if your visitors will be 40" (100 cm) away, your QR code should be of 4" (10cm).
Depending on the print quality and the distance to the QR code, I wouldn't recommend to make it smaller than 0.4" (1cm) from side to side.
Always remember to test it before printing it massively!
Last Updated: Mar 04, 2015 04:17PM UTC