how big is a 3/4 bed

A 3 size paper, specifically A3, measures exactly 297 mm by 420 mm (29.7 cm by 42 cm), or 11.7 inches by 16.5 inches. It is twice the size of A4 paper and is commonly used for small posters, drawings, diagrams, and menus. The A series paper sizes maintain a consistent aspect ratio, and A3 is a standard international size according to ISO 216.