The invention is directed to accurate calculation of a birefringence of a polymer stretched and oriented. Disclosed is a method for calculating a birefringence of a polymer in an information processing apparatus, having an amorphous state generating step including accepting input of a parameter, generating a model of the polymer on the basis of the parameter, and bringing the model into an amorphous state; a stretching step including stretching the model brought into the amorphous state; a birefringence calculating step including calculating a birefringence of the stretched model; and an outputting step including outputting the birefringence thus calculated.