Calculating distance on a map


I’m running a campaign in the Sword Coast, and like to provide consistent travel distance and time to my players. As far as I could find, there are no distance charts. And even if there were, they are unlikely to provide all locations (but I might stand corrected!).

A solution could be a piece of software which can open the high resolution Sword Coast map, in which I can draw lines, and which then tells me the length in pixels of the lines, so I could covert that back into miles, and ultimately derive a travel time.

Does anyone know of something to do this in?

Related:

  • Travel Chart for the Forgotten Realms