Apparatus for measuring belts, comprising: a first rangefinder (S 1) making first distance measurements from the first rangefinder to a belt having a regularly spaced topographical feature and advancing at a belt speed in a direction of belt travel transverse to the distance between the first rangefinder and the belt; a processor receiving the first distance measurements from the first rangefinder (S 1) and producing a first profile record (D 1) of a predetermined number of sequential first distance measurements; a second rangefinder (S 2) making second distance measurements from the second rangefinder (S 2) to the belt, wherein the second rangefinder (S 2) is offset from the first rangefinder (S 1) in the direction of belt travel by a separation distance (d s); wherein the processor receives the second distance measurements, produces a second profile record (D 2) of a predetermined number of sequential second distance measurements; wherein the processor is configured to determine the distance between consecutive positions of the regularly spaced topographical features on the belt from the belt speed and either: (a) an auto-correlation time delay (τ p1 ') between consecutive occurrences of the regularly spaced topographical feature in an auto-correlation (R 11) of the first profile record (D 1); or (b) a cross-correlation time delay (τ p) between consecutive occurrences of the regularly spaced topographical feature in a cross-correlation (R 12) of the first profile record (D 1) and the second profile record (D 2). a first rangefinder (S 1) making first distance measurements from the first rangefinder to a belt having a regularly spaced topographical feature and advancing at a belt speed in a direction of belt travel transverse to the distance between the first rangefinder and the belt; a processor receiving the first distance measurements from the first rangefinder (S 1) and producing a first profile record (D 1) of a predetermined number of sequential first distance measurements; a second rangefinder (S 2) making second distance measurements from the second rangefinder (S 2) to the belt, wherein the second rangefinder (S 2) is offset from the first rangefinder (S 1) in the direction of belt travel by a separation distance (d s); wherein the processor receives the second distance measurements, produces a second profile record (D 2) of a predetermined number of sequential second distance measurements; wherein the processor is configured to determine the distance between consecutive positions of the regularly spaced topographical features on the belt from the belt speed and either: (a) an auto-correlation time delay (τ p1 ') between consecutive occurrences of the regularly spaced topographical feature in an auto-correlation (R 11) of the first profile record (D 1); or (b) a cross-correlation time delay (τ p) between consecutive occurrences of the regularly spaced topographical feature in a cross-correlation (R 12) of the first profile record (D 1) and the second profile record (D 2). (a) an auto-correlation time delay (τ p1 ') between consecutive occurrences of the regularly spaced topographical feature in an auto-correlation (R 11) of the first profile record (D 1); or (b) a cross-correlation time delay (τ p) between consecutive occurrences of the regularly spaced topographical feature in a cross-correlation (R 12) of the first profile record (D 1) and the second profile record (D 2).