Determining the positions of nodes is essential in many applications and geographic routing protocols of Wireless Sensor Networks. Since localization is a fundamental component of sensor networks, the cost for localization itself should be minimized. In this paper, we focus on developing a localization algorithm which provides both low-cost and accuracy. Considering these requirements, we propose a novel range-free localization technique, called HCRL, which uses only the ratios of anchor-to-node hop-counts. HCRL satisfies low-cost with a single flooding from a small number of anchor nodes, and subdivides one-hop into several sub-hops by transmission power control to improve localization accuracy. Unlike previous work, we have conducted real experiments, which were made possible by using an external antenna with an omni-directional radiation pattern. The experimental results show that the performance of HCRL is superior to the conventional DV-Hop scheme with a small transmission overhead.