what are the dimensions of a piece of paper

The dimensions of a piece of paper can vary depending on the standard used. In the United States and Canada, the most common paper size is letter-sized paper, which is 8.5 inches by 11 inches. Other common sizes include legal size, which is 8.5 inches by 14 inches, and tabloid or ledger size, which is 11 inches by 17 inches. In the international standard, which is based on metric measurements, the most common paper size is A4, which measures 210 x 297 mm or 8.25 x 11.75 inches. The ISO 216 standard, which includes the A4 size, is based on the German DIN 476 standard for paper sizes. The A series of paper sizes is based on a geometric progression with easy-to-remember formulae, and each consecutive pair of values corresponds to the dimensions of a standard paper format in the series.