Because of the linear growth with time, the mean anomaly makes calculating the time of flight between two points on the orbit very easy. The mean anomalies for the two points are calculated and their difference is found. Knowing this, the ratio of this difference relative to the entire encompassing one orbit is simply equal to ratio of the time of flight to the period of one whole orbit (i.e. ).
When measured in radians the mean anomaly has a value of at the initial crossing of the orbit's point of periapsis, and a multiple of at any later crossing of the point periapsis. In the diagram below, the mean anomaly of point on the orbit around is given by angle (the angle ).
The point y is defined such that the circular sector area z-c-y is equal to the elliptic sector area z-s-p, scaled up by the ratio of the major to minor axes of the ellipse. Or, in other words, the circular sector area z-c-y is equal to the area x-s-z.