The Internet real-time applications are growing rapidly, and available bandwidth estimation is required. Available bandwidth estimation methods by end host have been studied e.g. Pathload and pathChirp. These methods parameterize probe packets volume and observe the delay variation to estimate available bandwidth. In these methods, probe packets give heavy overhead loads on the network. In this paper, we propose a new available bandwidth estimation method based on frequency of minimum RTT of probe packets in multi hop links. This method estimates bandwidth utilization and available bandwidth of a bottleneck link without severe network loads. Estimation accuracies are evaluated for available bandwidth by implementing the proposed method. The proposed method shows better performance than those of pathChirp and Pathload, requiring smaller number of probe packets and less estimation time simultaneously.