The dimensions of the A3 paper size as determined by the ISO 216 standard is 11.7 inches by 16.5 inches. A3 is mostly used for large drawings, images, architecture, computer-aided design and other forms of design-based graphic elements.
The A3 paper size is globally recognized with the exception of Canada, the United States and some South America countries; who instead use the ledger size. The A3 paper size is slightly shorter and wider compared to the Ledger size. An A4 paper is exactly half the size of an A3 paper. The dimensions in the A paper series are based on mathematical formulas, which range from A0 to A10. A0 is the largest.