Visit a free online mapping service, such as Google Maps or MapQuest.
Click on the "Get Directions" link on the home page to reveal two text boxes, one for the departing city ZIP code (point "A") and the second text box for the arrival city ZIP code (point "B").
Enter the 5-digit ZIP code into the text boxes. For example, if you want to calculate the miles between Carrollton, Texas and Bevery Hills, California, you would enter "75006" in the first text box and "90210" into the second box.
Press the "Get Directions" button to begin the calculation. On the next page, you should see a section labeled "Suggested Routes" with several routes you can take to get to your final destination. Depending on the route, your miles may vary slightly. For example, from Carrollton, Texas to Beverly Hills, California is 1,434 miles if you travel on Interstate-40 West.