A medical robotic system has functionality to determine and display information of a distance indicated by movement of one or more tools being robotically manipulated by an operator. The distance is determined using sensed robotic manipulation of the one or more tools. Information of the distance is displayed on the monitor so as to be visually associated with the movement and/or positions of the tools, such as a virtual tape measure that extends along with or between images of the one or more tools on the monitor or as a virtual ruler with the distance being indicated by a pointer. Alternatively, information of the distance may simply be indicated on a digital read-out shown on the monitor that is displayed and continually updated with the movement of the one or more tools.