The increase in life expectancy fueled by the development of medical technology and the aging of the world’s populations have created a labor shortage in the nursing care industry in Japan. In addition to supporting the daily lives of seniors, elderly care facilities monitor and manage the amount of physical activity of their occupants to maintain their health. To reduce the burden of such work, activity amount estimation has been proposed using acceleration sensors, smartphones, and cameras, although it has not been widely used due to installation costs. Therefore, this study proposes a method that estimates the number of steps taken using BLE beacons as sensors to achieve a low-cost activity-amount estimation. A BLE beacon is attached to the soles of footwear, and the number of steps taken by a person is estimated from the received radio wave strength that changes with walking movements. In an evaluation experiment, participants walked 100 steps at an arbitrary speed, and then the actual number of steps was compared with the estimated number. We found that the estimation accuracy was 91.6%.