How to calculate realistic road length?

I am looking for to calculate the road length in graphhoper but not getting any idea.
What is the way to get the length?
Anybody give some hint here?

I think you should try with lat and long. I hope you will find your solution.

Do you mean the calculated route distance?
That can be retrieved from returned path (see documentation).

I mean calculate road length, not between two points Euclidean distance.