For EAN-13 retail barcodes, the standard size is 38mm wide x 25mm high. The minimum size we recommend for EAN-13 barcodes is 30mm wide x 20mm high. For complicated QR codes, we recommend a minimum size of 30mm wide x 30mm high. For less complicated QR codes we recommend a minimum size of 20mm wide x 20mm high. Below are examples of a very simple QR code (left), a typical QR code (middle), and a very complicated QR code (right):