A3.0

The A3.0 is an elongated paper size defined in ISO 5457. It combines the 297 mm short side of an A3 sheet with the 1189 mm long side of an A0 sheet. This results in the A3.0 having dimensions of 297 mm x 1189 mm. With an aspect ratio of 4:1, the A3.0 is four times as long as it is wide. The total surface area of an A3.0 sheet is 353,793 mm2 or 0.3538 m2.

As part of the ISO 5457 standard introduced in 1999, the motivation behind the A3.0 and other elongated sizes was to provide more flexibility while maintaining A-series width-to-length ratios. For certain technical drawings and designs, an elongated orientation on a longer sheet at standard proportions is beneficial. The A3.0 format serves this need with its extra long 1189 mm dimension compared to standard A3. The A3.0 has been adopted by ANSI/ASME Y14.1 for use in the United States in addition to regular A3 and other A-series sizes. In summary, the elongated A3.0 allows for narrow A3-ratio drawings on an extended sheet while preserving the familiar ISO A-series proportions.