Distance between cities

Worked example: Austin to Nashville

Using the capitol coordinates stored on this site (30.274, -97.74 and 36.166, -86.784), the haversine distance is 1,210 km or 752 miles. The line leaves Austin heading 54° (NE).

If you search the city names instead, Photon returns the point OpenStreetMap uses for each city, usually near the center. The result can differ from the capitol figure by a few miles.

How to use it

1. Type the first city in Origin and pick it from the list. Add the state or country if the name is common.
2. Type the second city in Destination and pick it.
3. The map draws the straight line and the card shows the distance in kilometers, miles, and nautical miles, with the initial, final, and rhumb bearings.
4. To adjust an end, click the map: the first click moves the origin if none is set, otherwise the destination.

Which point stands for a city

A city covers many square miles, so any distance between two cities depends on the point chosen for each. This tool uses the point the geocoder returns for the name you pick, which for most cities is a node placed at the traditional center. You can also click the map to set each end yourself.

For the largest metro areas, the gap between two reasonable choices of center can be several miles. That is why published city distances rarely agree to the mile.

The math

The distance is the length of the great-circle arc between the two points on a sphere of radius 6,371.0088 km, computed with the haversine formula. The tool reports miles, kilometers, and nautical miles, plus the start and end bearings and the rhumb line heading.

For US state capitals, a ready-made table of all 1,275 pairs is on the state capital distance page.

Cities with the same name

Springfield, Portland, and Columbus each exist in several states. Type the state or country after the name and pick the right line from the search list. The map marker shows which one you chose before you read the distance.

Common mistakes

The most common error is picking the wrong city from the search list, such as Paris, Texas instead of Paris, France. Check the marker before reading the number. The second is comparing this straight-line figure with a road distance from a route planner; the road is always longer, and on winding routes the gap can be large.