Work machine orientation calculating device, hydraulic shovel orientation calculating device, and work machine

A work machine orientation calculating device is provided in a work machine and includes: a measuring device that detects angular velocity and acceleration; an orientation angle calculating unit that finds the orientation angle of the work machine from the angular velocity and the acceleration detected by the measuring device; a first complementary filter for which a first cutoff frequency is set and that outputs a first orientation angle by reducing noise contained in the orientation angle found by the orientation angle calculating unit; a second complementary filter for which a second cutoff frequency that differs from the first cutoff frequency is set and that outputs a second orientation angle by reducing the noise contained in the orientation angle found by the orientation angle calculating unit; and a switching unit that outputs by switching between the first orientation angle and the second orientation angle according to the measuring device status.