A sensor-equipped wheel support bearing assembly includes a sensor unit provided in an outer member, which serves as a stationary member. The sensor unit has a strain generator and a sensor for detecting a strain occurring in the generator. A principal load estimator estimates the load acting on the wheel, with the use of an average value of a signal from the sensor, and an amplitude processed load estimator estimates the load, using amplitude of a signal wave outputted from the sensor, resulting from passage of rolling elements. A drift amount estimator estimates a drift amount of an estimated load output utilizing the average value and the amplitude, which is used to correct the estimated load.