STEERING COMPUTING DEVICE

A steering computing device for calculating state quantity of a steering apparatus includes a processor. The processor is configured to execute a steering angle variable acquisition process, an output shaft angle variable acquisition process, and a joint angle variable calculation process. The steering angle variable acquisition process is a process of acquiring a value of a steering angle variable. The output shaft angle variable acquisition process is a process of acquiring a value of an output shaft angle variable as a variable indicative of a rotation angle of an output shaft of the steering apparatus. The joint angle variable calculation process is a process of calculating a value of the joint angle variable. The joint angle variable is a variable defining an angle formed between an axial direction of an input shaft of the steering apparatus and an axial direction of the output shaft.