A radius map provides the distance between a center point to the circumference of a circle. Radius maps display a circumference of equal distance around a fixed center point. Companies often provide radius maps to show service and/or delivery areas. For example, a moving company will service within a 30 mile radius and will not travel any farther. Typical radius maps can provide distance in miles or kilometers in 1 to 5 mile intervals. You can calculate mileage with a few simple formulas. Radius maps only provide the distance in a straight line from the center to the edge of the circle.
Things You'll Need
- Pen and Pad
- Radius map
Find the distance of the radius on a radius map. Most radius maps will disclose the length of the radius. For example, if the outer circle is 25 miles away from the center, the radius will be 25 miles.
Plot the destinations on the map. Place a dot at each stop or destination.
Using a ruler, measure the distance between the center point to the outside perimeter of the circle. Write down the measurement. This will help create a legend, it should state X inches equals Y miles, that is the ratio of inches to miles. For example, if the radius equals 25 miles and you measured 5 inches with a ruler; this means that every inch on the map will equal 5 miles -- 25 miles divided by 5 inches equals 5 miles per inch, this is the legend for this particular example.
Using a ruler, measure the distance between the center point and one of your destination points.
Use the legend to complete the distance in miles. If the first destination is 2 inches away, using the ratio of 5 miles per inch, the first destination will be 10 miles away. Repeat steps to find multiple destinations on the radius maps.