Distance is one of the key factors for transportation and logistics. Geological road distance is different from euclidean distance so the circuity factor (CF), the ratio of road and euclidean distances, should be considered for planning projects and designing infrastructures. The purpose of this study is to calculate the national and regional circuity factors and compare them with values of other countries. We also estimate regional CFs for states and metropolitan areas. The national circuity factor of South Korea is 1.26 which is higher than USA and smaller than Japan or EU. The largest and least circuity factors of states are 1.435 (Gangwon province) and 1.218 (Gyeonggi province), respectively. Generally metropolitan areas show much lower circuity factors than states. Our results could be used for planning infrastructures and facilities of transportation and logistics.