Flight Miles Is There A Site That Counts Flight Miles, Without Making A Reservation For A Flight?

Is there a site that counts flight miles, without making a reservation for a flight? - flight miles

I kinda need to see, the miles to fly from one place to another for homework .... and .... I'm just too lazy to use an atlas. Thus, there is a site that you define a starting point and then his goals and see the miles of flight, flight booking can?