How to calculate the distance between two selected vertices? Now I have got a new problem. I want to measure the distance between 2 selected vertices but I do not know how to do that in Blender. Can you help me? Thanks a lot.
You could use MeasureIt addon that you can enable from User Preferences (ctrl+alt+u), Add-ons tab:



Or you could also use an inbuilt ruler that you can find in the Tool Shelf(t panel), Grease Pencil tab that you can snap to vertices holding ctrl while dragging: