Maximum Magnification On 55-250 Zoom
Maximum magnification on the 55-250mm is at the 250mm end of the zoom range. According to Canon this gives a macro ration of 0.31 - very nearly 1/3 life size. An object about 70mm / 2.8 inches across would stretch across the full frame at that distance. If you want to go closer extension tubes or the Canon 500D or similar close up filter can provide extra magnification.