This paper is the most used in Europe and in the world, the database format.
Most individuals buy and use A4 printers and scanners.
A4 in its most widely used weight (80g / m²) is a leaf of a mass of 5 grams, which dispenses with the use of scales letters if you know the weight of the envelope used.
Paper Size A4 : 210 x 297 mm or 21 x 29.7 cm
Paper Size A4 : 8.3 x 11.7 inches
A4 paper size compared to others paper sizes: