A parallax calculation apparatus includes an acquisition unit and a controller. The acquisition unit acquires a standard image and a reference image captured by a stereo camera. From each of the standard image and the reference image, the controller extracts lines from a plurality of lines parallel to a first direction in an image space corresponding to a baseline direction of a three-dimensional coordinate space. The controller calculates a parallax between the standard image and the reference image based on a plurality of pixels included in the extracted lines.