DINA4Blatt

DINA4Blatt, short for DIN A4-Blatt, denotes the standard sheet size of paper used in many countries. It corresponds to the A4 size defined by the ISO 216 standard (formerly DIN 476), with dimensions of 210 mm by 297 mm. The term reflects its origin in the German standardization tradition, though it is now widely used in German-speaking contexts and beyond.

The A-series is based on an aspect ratio of 1:√2, which allows any size to be halved to produce the next size with the same proportions. An A4 sheet is obtained by halving an A3 sheet (and, in turn, from A0). This design enables consistent scaling for printing, copying, and folding while preserving the same shape.

A4 sheets are the most common format for office documents, letters, reports, forms, and educational materials. They are widely supported by printers, copiers, scanners, and filing systems. Paper weights typically range from 60 to 120 g/m2; 80 g/m2 is common for everyday printing.

The A-series was developed in Germany and codified as DIN 476 in 1922 and later became ISO 216, adopted internationally in 1975. The DIN A4 designation remains the standard reference for this size in many German-speaking regions, while many other countries use the ISO naming conventions.