The author and his colleagues have been engaging in the study to estimate ice forces on Multi Conical Legged Structures (MCLS). They constructed a method to estimate ice forces on MCLS and gained a partial succession. It was recognized that the method must consider effects due to non-simultaneous occurrence of ice failure. In this study, the author employed the Monte Carlo simulation to consider the effects of non-simultaneity and obtained a better correlation to experimental results. Methods to calculate design ice force and simplified method to obtain a first look estimation of ice force were also proposed.