A distance measurement apparatus that calculates distance information based on first and second images, includes a first calculation unit that calculates, for each pixel to which distance calculation is performed, distance information corresponding to the pixel on the basis of a local area of a number of local areas in the first image, including the pixel, and a local area of a number of local areas in the second image, corresponding to the local area in the first image; a second calculation unit that calculates a non-similarity value between the local area in the first image and the local area in the second image; a determination unit that determines whether the non-similarity value is greater than a threshold; and a third calculation unit that calculates a ratio of the number of local areas for which the non-similarity value is determined to be greater than the threshold in a predetermined area to the number of local areas in the predetermined area.