A track count estimator is provided for an optical storage device operating in either a CD-ROM mode or a DVD mode during a track seek. The track count estimator includes a state estimator to determine current and predicted estimates of the position and velocity of an optical pickup in the optical storage device according to the following equations:Current Estimate: X(k.vertline.k)=X(k.vertline.k-1)+K(Z(k)-X.sub.1 (k.vertline.k-1))Predicted Estimate: X(k+1.vertline.k)=Ad.multidot.X(k.vertline.k)The input to the state estimator can be selected from a CD-ROM signal (if the optical device is operating in a CD mode) or a DVD signal (if the optical device is operating in a DVD mode), the selected signal representing a half-track position error. An error signal is then generated which is processed separately in position and velocity portions of the state estimator. The output of the position portion is a track count signal which is used by the optical storage device to determine the position of the optical pickup relative to a destination track. Track counting with the present invention provides higher resolution than conventional methods and is less prone to noise, dropouts and defects, thereby decreasing overall seek times while increasing seek accuracy.