In this study, a generalized shape of the heat sink for most of the commercial LED light bulbs was considered. The thermal resistance of a radial heat sink with triangular fins on a circular base was investigated at different angles. A numerical model with the consideration of natural convection and radiation was established to investigate the effects of the Rayleigh number, finning factor, porosity factor, installation angle, and radius of the heat sink base. The numerical model was validated through experiment. Then, based on numerical results, a correlation was suggested to estimate the degree of enhancement of cooling performance between the radial heat sinks with and without triangular fins.