A2.0

The A2.0 is another elongated paper size defined in ISO 5457. It combines the 420 mm short side of an A2 sheet with the 1189 mm long side of an A0 sheet. This results in the A2.0 having dimensions of 420 mm x 1189 mm. With an aspect ratio of 2√2:1, the A2.0 has the unique property of being the same proportion as A2, just scaled up. The total surface area of an A2.0 sheet is 499,980 mm2 or 0.4999 m2.

Like the other ISO 5457 elongated sizes, the A2.0 was introduced in 1999 to add flexibility while maintaining the width-to-length ratio consistency of the standard A-series. The idea is that technical drawings and designs sometimes need a particular elongated orientation that fits better on a longer sheet at the same proportions. The A2.0 allows for this with its extra long dimension compared to A2. Along with the other ISO 5457 sizes, the A2.0 has been adopted by ANSI/ASME Y14.1 for use in the United States in addition to the normal A2 and other standard sizes. Overall, the A2.0 format provides an elongated dimension for narrow A2-proportioned drawings while keeping the familiar A-series ratio.