To provide a method for calculating the total number of regular-shaped members by which processing for calculating the number of required regular-shaped members such as tiles or panels is performed by a computer when regularly arraying thee regular-shaped members in an area determined by the design drawings of a building.

The calculation is performed for arraying and spreading various regular-shaped members such as tiles, floor materials or panels in the area determined according to a room layout drawing 3 or the like of the building. A storage device 4 stores reference image information 5. Arithmetic processing is applied to a dot matrix generated by a dot matrix data generating means 8 while referring to the reference image information 5 and the number of required regular-shaped members is counted. Thus, when the number of required regular-shaped members is counted by utilizing the reference image information, the number of tiles of full width, the number of tiles of 1/2 width and the number of tiles of 1/4 width can be respectively provided. The calculated result is used as data for order for ordering tiles and delivering them to the site of construction and can be utilized as information showing how to array tiles to a person in change of construction.