A method of estimating a front obstacle detection distance includes detecting an obstacle from a front image of a vehicle, extracting coordinates of a lower end portion of a detection box of the detected obstacle, calculating a projected line on real world coordinates based on the extracted coordinates of the lower end portion, searching for a point or a line through which the projected line passes on a detailed map, and calculating a distance to the point or the line through which the projected line passes on the detailed map from a position of the vehicle.