QR Code Size for Wall Posters & Storefront Windows

Wall posters, subway ads, conference bulletin boards, and storefront window graphics operate at medium viewing distances. Pedestrians rarely walk directly up against a window or wall to scan a code; instead, they scan from a comfortable arm-length or walking distance of 80 cm to 150 cm (approximately 3 to 5 feet). Using the optical 10:1 rule, a QR code on a wall poster must measure at least 80 mm × 80 mm (3.2 inches), with 100 mm to 120 mm recommended for busy pedestrian corridors. Sizing smaller creates frustrating scan failures for passing crowds. In storefront windows, double-pane glass reflections and street glare further degrade optical contrast, making Level Q or Level H error correction essential. Our calculator guides you through physical dimensions, eye-level mounting heights, and 300 DPI vector production to ensure your event posters and retail promotions capture every passerby effortlessly.