In the loss distribution approach for operational risk capital modeling, severity and frequency are modeled separately and then combined to obtain the aggregate loss distribution and capital. From the point-of-view of analytic approximations, the realm of modeling can be divided into four quadrants, based on whether the tail of the severity distribution is light or heavy, and whether the expected frequency is low or high. We present asymptotic approximations for operational risk capital that are relevant in these quadrants. The accuracy of the approximations and their practical usage are discussed.