To provide a tire designing method, a tire designing program, and a tire designing device which can efficiently design a pneumatic tire capable of satisfying the requirement for at least two tire performance.

In the tire designing method for the pneumatic tire having at least one layer of a belt layer, the range from a tire equatorial plane to a belt end part among the belt layers is divided (step S1) into a plurality of areas in the tire width direction, a designing element of belt structure in each area is set (step S2) to a design variable, a target function composed of an evaluation characteristic value having an effect on at least two tire performance is set (step S3), the design variable of each area where the target function is the optimum value is determined (step S4), and the pneumatic tire is designed (step S5) based on the determined design variables.