# What is A4 size?

The A4 is paper size of 210 mm by 297 mm. The A4 size is the most commonly used paper sizes in Europe and Japan. The size is an A0 which is then halved four times. On this page, we answer the following question: What is A4 size?

### A0 relative to A4

An A0 has a surface area of 1 m². The length to width ratio of an A0 and all sizes of the A-series are √2:1. The area of an A4 is ½ × ½ × ½ = 1/16 m².

### A4 paper size international

A4 size is an international paper size from the DIN quotation (DIN 476 from 1922). This standard has been changed to the ISO 216 standard. In parts of Germany people still speak of DIN A4. An A4 is part of the series A0, A1, A2, A3, A4, A5, A6, A7 and A8.

In North America and parts of Latin America, the ISO 216 standard is not used. Here US Letter size of 8½ by 11 inches (279.4 mm by 215.9 mm) is used. These 6 mm wider and 18 mm shorter than A4. The master printers and copiers can be set to both sizes.

### Weight and mass

A commonly used weight for A4 paper is 80 grams. The 80 grams is for a paper of A0 size. A whole sheet of A0 paper is 80 grams. An A4 paper is 80/16 = 5 grams.

### Different values

If you are looking for A4 paper size in different values such as inches, centimeters, millimeters and pixels, choose from the questions below: