A physical quantity distribution calculation program for visualizing a physical quantity distribution in a target space is disclosed. The program causes the computer to perform processes of: based on positional information on a plurality of grid points and physical quantities obtained respectively at the plurality of grid points by the numerical analysis, grouping the grid points into groups of neighboring grid points having the same physical quantity; and determining the physical quantity to be visualized by each of a plurality of pixels which are fewer than the grid points, the determining process includes; extracting at least one group including at least one of grid points corresponding to the pixel, identifying the group including the largest number of grid points among the extracted groups, and determining that the physical quantity at the grid points belonging to the identified group is the physical quantity to be visualized by the pixel.
