It depends on the exact 3D printer you're using. Each of them has a maximum build volume. Typical maximum size for 3D desktop printers: 150-300 mm per side. Large prints normally take a very long time to complete, often hours or even days. Large 3D models can be split into pieces, printed and assembled into larger objects unless they fit into a specific 3D printer. Industrial 3D printers can handle much larger sizes – but they're very expensive.