What is the total diameter of earth?

''Earth'' - Only know planet in the entire universe to sustain life in humanly form.. there may be existence of life on any other planet with life support features and that life may be bacterial or any other.. Lets talk about our earth as it is not a perfect sphere so obviously it will not be having a constant diameter. Thus the dimensions are classified as follows :

1. Mean Diameter                  :    12,742 km

2. Equatorial Diameter         :    12,756.2 km

3. Polar Diameter                  :     12,713.6 km