There are several common book sizes. These sizes are based on the most cost-effective use of standard paper sizes (ie how many pages can be fit onto a sheet). The choice is yours, but we can advise you if the size can be changed slightly to make it more economical. The list below shows standard book sizes but remember that books can be almost any size you wish, and portrait, landscape or square format. Note: All specs below are shown width x height. • 'A’ Format: 110 mm x 178 mm • Penguin: 111 mm x 181 mm • 'B’ Format: 129 mm x 198 mm • Demy: 138mm x 216mm • A5: 148 mm x 210 mm • Royal: 156mm x 234 mm • Royal Octavo Wide: 170 mm x 234 mm • American: 210 mm x 279 mm • US trade (American Royal) 152 mm x 229 mm (6" x 9") • American Narrow: 200 mm x 279 mm • A4: 210 mm x 297 mm • Custom sizes (portrait or landscape format) Learn more about book binding options or Contact us to discuss your book PS We are rated five-stars on Google