The design and construction costs of tall buildings are relatively higher than those of general buildings due to their complex spatial configuration and high density. Since the economic impact from the high-rise buildings is quite large, more careful approach is needed at the initial stage of the planning based on the actual efficiency analysis. This research is performed to develop the method of measuring the mass efficiency quantitatively to enhance the economical aspect of high-rise buildings. Brief result of the research is that, unlike the general prejudice to comparative efficiencies among certain geometric shapes, actual estimated differences are not that great in about 4% ranges. Other comparative evaluations can be observed in the paper such as the differences between the regular and the irregular shapes.