An object detection device includes a first sensor, a second sensor, a calculation range selector and an estimator. The first sensor outputs a radio frequency (RF) signal, receives a reflected RF signal reflected from an object, and obtains a first measurement value for the object based on a received reflected RF signal. The second sensor obtains a second measurement value for the object by sensing a physical characteristic from the object. The physical characteristic sensed by the second sensor is different from a characteristic of the object measured as the first measurement value obtained by the first sensor. The calculation range selector sets a first reference range based on the second measurement value. The first reference range represents a range of execution of a first calculation for detecting a position of the object using a first algorithm. The estimator performs the first calculation only on the first reference range using the first measurement value, and generates a first result value as a result of performing the first calculation. The first result value represents the position of the object.