We propose a novel indoor item-finding system using radio frequency identification (RFID) passive tags attached to various items, furniture, and walls. The proposed system assists the user in finding a missing item by indicating the estimated distance from the user’s location to the target item’s RFID tag. The distance to the target is estimated by using detected tags near the user, and their detection history. Our system is low cost because the system uses passive RFID tags without battery and it is not necessary to record the object and the position every tag is attached to manually. The system has wide range of tag-detectable areas because the system can estimate the long distance by using the pseudo distance of nearby tags to each other. We simulated and confirmed that our algorithm for calculating the pseudo distance could adequately approximate the real distance after a sufficient number of RFID scans. We also conducted a user study in an actual room and confirmed that our system reduced the amount of time to find the target, the quantitative physical movement, and the subjective workload.