Since most medical facilities and medical personnel are concentrated in urban areas in South Korea, an imbalance of access to medical facilities causes a gap in medical resource availability between urban and rural areas. Accessibility to medical facilities is a means of assessment that evaluates a measure of inequality in utilization of medical resources. The evaluation of accessibility uses Euclidean distance, in general; however, this method has its limits in that Euclidean distance cannot reflect actual distance. This study aims to estimate real road distance from village halls to medical facilities in rural areas using Open Application Programming Interface (Open API) of an internet portal site. Using real road distance, we evaluated medical accessibility and compared it with Euclidean distance. The accessibility to primary medical institutions was valued relatively well, but secondary and tertiary medical institutions were vulnerable in Pyeonchang-gun. Comparing Euclidean distance with real road distance from village halls to medical facilities, real road distance appeared to be approximately 1.4 times that of Euclidean distance. This calculation is similar to the circuity factor of Gangwon-do in Korea that estimated to fix the limits of Euclidean distance and assumed real road distance.