Returns the integer portion of EXPR. If EXPR is omitted, uses $_ . You should not use this function for rounding: one because it truncates towards 0 , and two because machine representations of floating point numbers can sometimes produce counterintuitive results. For example, int(-6.725/0.025) produces -268 rather than the correct -269; that's because it's really more like -268.99999999999994315658 instead. Usually, the sprintf, printf, or the POSIX::floor and POSIX::ceil functions will serve you better than will int().