An information processing apparatus includes an acquisition unit configured to acquire a first phase signal and a second phase signal that are acquired by measuring a rotation of a moving object, and a calculation unit configured to calculate a rotational angle by an iterative calculation so as to satisfy a relational expression bearing an arctangent. The relational expression bearing the arctangent uses a first cosine wave and a second cosine wave at a higher harmonic of the first cosine wave for the first phase signal, and a first sine wave and a second sine wave at a higher harmonic of the first sine wave for the second phase signal. The first phase signal and the second phase signal may, for example, be analog signals having a wave shape.