To easily and properly determine a position of a center hole of a crankshaft.

A center hole determination method determines the center hole of a material crankshaft formed by molding with a cope and a drag, and includes first to fourth steps. In the first step, shape data of each part molded with the cope and drag is obtained. In the second step, measurement data of each part is compared with the corresponding design data to calculate a mismatch amount caused by mismatch of each part. In the third step, based on the mismatch amount, the data corresponding to the mismatch amount is interpolated to reproduce actual shape data. In the fourth step, a center hole is determined so that a rotation balance of the material crankshaft is within a predetermined range based on the actual shape data.