Aug 11, · A size is the functional equivalent to UK A4 and is 8.5in by 11 inches. As the letters increase the short dimension is doubled. E.g: B size is 17×11 inches (roughly A3 – also called ledger), C size is 17×22 inches, D size is 34×22, and E size (typically a ‘full-size” engineering drawing) is 34×44.