Is A4 bigger than A3?

David Girones

Updated on:

Set of different paper sizes

Standardized paper sizes, being units of measurement, have existed for many years and greatly facilitate the comparison of similar items. The list of units of measurement is endless and encompasses not only paper sizes but also clothing sizes, distances, electronic device memory, weights, scales, and much more.

The fact that there are so many elements that are compared to each other using standardized measurements makes it sometimes difficult to remember the relationship between them, and in many cases the origin dates back to other times or comes from other languages and/or cultures.

For example, in the case of paper sizes, which is the topic of today’s discussion, the following question may arise: Is A4 bigger than A3?

For some, this question may seem pointless, as if you know the size of an A4 and an A3, you will clearly know which of the two is larger. However, taking into account that in the case of DIN paper sizes, the number can be misleading, we will proceed to answer the question below.

Comparison image to know the answer to the following question. Is A4 bigger than A3? The answer is clearly no

Is A4 bigger than A3?

DIN A4 paper size is smaller than DIN A3 paper, and they are two consecutive paper sizes within the DIN A series scale. 
A4 paper size is 210 mm x 297 mm, while A3 paper size is 297 mm x 420 mm.

The Origin of Paper Size Standardization: The DIN Series

The history of the DIN paper size standardization series dates back to the early 20th century, in a context where the paper and printing industry in Germany was fragmented. There was a wide variety of paper sizes, which generated compatibility problems and made it difficult to exchange documents between companies and organizations.

After a process of study and analysis, the DIN (Deutsches Institut für Normung, or in English, the German Institute for Standardization) published in 1922 the DIN 476 standard.

DIN 476 defined the A series of paper sizes. This series was based on a rectangular format with an aspect ratio of 1:√2 (1:1.414). This special ratio means that each DIN size can be divided in half to create two pages of the next smaller size in the DIN A series.

Remarkably clever!

The adoption of the DIN paper size standardization series was a resounding success, and it quickly became the dominant standard in Germany and, subsequently, in much of the world.

DIN A Series Paper Sizes

As we have mentioned, the DIN standardization model is the most widely used worldwide, so comparing different DIN sizes is quite common.

In the case of the DIN series A standardization standard, DIN A0 is the largest size and its measurements are 841×1189 mm, which corresponds to an area of 1 square meter.

From here on, the relationship is always identical and each higher number corresponds to the previous paper size divided into two equal parts. For example:

  • DIN A2 size is 420 mm x 594 mm
  • An A3 is an A2 divided by half 297 mm x 420 mm
  • An A4 is an A3 divided by half 210 mm x 297 mm
DIN A0 paper with each and each subsequent size including A4 and A3

DIN Paper Size Comparison Table: Where is A4 and A3 in the Table?

SizeDimensions (mm)Dimensions (cm)
DIN A0841 x 118984.1 x 118.9
DIN A1594 x 84159.4 x 84.1
DIN A2420 x 59442.0 x 59.4
DIN A3297 x 42029.7 x 42.0
DIN A4210 x 29721.0 x 29.7
DIN A5148 x 21014.8 x 21.0
DIN A6105 x 14810.5 x 14.8
DIN A774 x 1057.4 x 10.5
DIN A852 x 745.2 x 7.4
DIN A937 x 523.7 x 5.2
DIN A1026 x 372.6 x 3.7
Comparative table of the DIN A series paper standardization system

Conclusion on Which is Larger, A4 or A3

The DIN paper size system is very easy to remember. Just remember that A0 is the largest size, and each subsequent number represents a size that is half the size of the previous one. So, A4 is smaller than A3..

Other Paper Size Comparisons

Photo by Karolina Kaboompics