How to Use: Distance Calculator

The Distance Calculator shows the air distance, also known as the great circle distance, between any two locations in our database.

How to Use the Distance Calculator

1. From location: Select the location you wish to use as the starting point for your calculation. If it doesn't appear in the drop-down, click on Search, enter the city into the search field, select it from the list of suggested locations, and click Select.
2. To location: Select the location you wish to use as the destination point of your calculation.
3. Click on Calculate Distance.

FAQ: Troubleshooting

Why does it show the wrong distance?

If you believe that the calculator shows the wrong distance, please consider the following before sending us your error report:

• The Distance Calculator shows the air distance or great circle distance between the two locations you pick. It does not show road distances.
• The result is shown in different units at the top of the results page. Perhaps you looked at the wrong unit?
• Planes often don't take the shortest route between two locations, so a flight route may be considerably longer.

If you still think the calculator shows the wrong distance, please let us know.

Why do I have to start from scratch every time?

You don't. To modify the current calculation, click on Modify From or To location under the sub-heading “Find the distance between other locations” on the results page.

Why is the red line on the map not straight?

Because the Earth is a sphere, a straight line looks curved when you project the Earth's surface onto a flat surface (like your computer screen).

Why is the wrong local time shown below the results?

At the bottom of the results page, we provide a comparison of the local times in the selected locations at the time when the page was loaded. This is meant as a general comparison, not a substitute for our World Clock, so the time shown here does not update until you refresh the page.

Why do planes take longer routes?

Planes often do not follow the shortest route between two locations. Reasons can include weather conditions, security considerations, or available infrastructure.

What's more, the calculator shows distances at sea level. Since planes fly at a considerable altitude, they have to travel a longer distance to get from point A to point B. For example, the distance increases by about 0.2% for a plane flying at an altitude of 40,000 feet, even if it follows the shortest possible route.

Why isn't my town included?

The Distance Calculator includes all 5000+ locations in our database. If your city doesn't appear in the drop-down when you set up a calculation, click on Search, enter the city into the search field, select it from the list of suggested locations, and click Select.

Some of our services also include millions of additional locations provided by the GeoNames database. However, these GeoNames locations cannot be selected in the Distance Calculator yet.

FAQ: General Info & Instructions

Does the calculator show road distances?

No. It only shows the air distance between the locations you pick.

What is the great circle distance or air distance?

The air or great circle distance is the shortest distance between any two locations on Earth as measured by drawing a path along the Earth's surface at sea level.

Is it possible to calculate the distances between more than two cities?

No, the Distance Calculator currently only shows the air distance between two cities at a time.

However, the Distance Signpost shows the distances between one location and multiple locations. Click on one of the See other cities near... links on the Distance Calculator results page to view the Distance Signpost for either the start or the end location you selected.

Is it possible to get an overview of cities around the selected cities?

Yes. Click on one of the See other cities near... links on the Distance Calculator results page to get to the Distance Signpost showing cities around the selected location.

The initial heading is the direction in which you would have to travel from location A to follow the shortest route to location B. The final heading is the direction in which you would arrive at your destination. Because the Earth is a sphere, the initial heading differs from the final heading, especially over long distances.

The headings are stated in degrees, with 360 in a full circle, counted in a clockwise direction from north. Like on a compass, north is 0 degrees, east is 90 degrees, south is 180 degrees, and west is 270 degrees. All headings are based on true north.

Are the headings based on true north or magnetic north?

All headings are based on true north.

What is the difference between heading, course, and bearing?

While there is a difference in some contexts, such as aviation, it is irrelevant for the Distance Calculator. Here, all terms refer to the direction along the direct line between the selected locations.

If you are in a plane, heading refers to the direction in which the plane's nose is pointing, course is the direction the plane is moving, and bearing is the direction in which your destination lies.

How do longitudes and latitudes work?

They are explained here.

How does your algorithm work? Can you help me program my own?

We are a small team with very extensive websites to manage, so, unfortunately, we do not have the capacity to share detailed information about our algorithms or provide programming help.