The 767-400ER fuselage adds 11 feet (3.4 m) to the baseline 767-300 airframe. The 767-400ER provides approximately 12 percent more seats -- accommodating 245 passengers in a three-class configuration and 304 passengers in a two-class configuration -- compared with 218 and 269, respectively, in the 767-300 version. The added seats will reduce seat-mile costs relative to the 767-300ER, which already offers airlines the lowest operating costs in its class.