I use Google Earth Pro to measure distance etc. Use the ruler on the toolbar and choose circle and miles. The radius is measured from the point you place your mouse as a beginning point. You can slide it in or out to measure different radius distances from the point of beginning.What is a good map to use to find the radius of where you live, ? looking for a map that I can put my zip or miles in from were I live so I know what and how far I can pick up .