Introduction
The As The Crow Flies Distance Calculator tells you the straight-line distance between any two places on Earth. A crow does not follow roads. It flies straight. This tool measures that same straight path, also called the great-circle distance.
Type in two cities, addresses, or landmarks. You can also click two spots on the map or paste latitude and longitude. The calculator then shows the distance in miles, kilometers, and nautical miles. It also gives you the compass direction to travel, the midpoint between the two places, and how much of the Earth's circumference your trip covers.
You get more than one number. The tool pulls in the real driving distance and drive time, then shows how much longer the road trip is than the crow-flies path. This is called the detour percentage. You can also see the time zone gap and the elevation at both spots. A chart compares the straight line and the road side by side.
Want to know how the math works? A step-by-step solution shows every part of the Haversine formula with your own numbers filled in. This helps students, pilots, hikers, planners, and anyone curious about how far apart two places really are.
How to use our As The Crow Flies Distance Calculator
Enter a start point and an end point, and the calculator shows the straight-line distance between them in miles, kilometers, and nautical miles, plus the bearing, midpoint, driving distance, time zones, and elevation.
Quick examples: Tap a button like "New York → London" to load a sample trip and see the results right away.
From (start location): Type a city, address, or landmark. Matching towns and cities appear in a drop-down list as you type; for a street address or landmark, press Calculate to look it up. You can also paste coordinates like 40.71, -74.01. Click the crosshair button to use your own location.
To (end location): Type your destination the same way, choose a suggestion, or paste its latitude and longitude. The crosshair button works here too.
Interactive map: Click the map to drop your green start pin, then click again to drop the red end pin. The dashed line shows the crow-flies path. Use the Fullscreen button for a bigger view.
Calculate, Swap, and Clear: Press Calculate to run the numbers. Swap flips the start and end points. Clear resets everything so you can start over.
Chart distance unit: Pick miles, kilometers, or nautical miles to change the units in the straight line vs. road distance chart.
What "As the Crow Flies" Means
"As the crow flies" is the straight-line distance between two places. It is the shortest path from point A to point B, measured over the Earth's curved surface. Roads, rivers, and mountains are ignored. A crow can fly right over them, so the saying stuck.
Why It Is Called the Great-Circle Distance
The Earth is round, so a "straight line" on a globe is really a curve. That curve is called a great circle. It is the largest circle that can be drawn on a sphere, like the equator, and its arc is the shortest distance along the surface between two points.1 Any two spots that are not exactly opposite each other sit on only one great circle, and the shorter arc between them is the crow-flies distance.1 On a flat Mercator map a great circle appears as a curve, which is why long flights look bent.1 The plane is not making a detour. It is following the shortest real path.
The Haversine Formula
This calculator finds the crow-flies distance with the Haversine formula, a formula of spherical trigonometry.1 It takes the latitude and longitude of both points, turns those degrees into radians, and works out the angle between the two spots as seen from the center of the Earth. That angle is then multiplied by the Earth's mean radius, about 6,371 km, to get the distance.2 That radius is about 3,959 miles. On a flat plane, the same job is done by the Pythagorean theorem.
- Latitude tells how far north or south a place is.
- Longitude tells how far east or west it is.
- The result works anywhere on Earth, even across oceans.
Straight Line vs. Driving Distance
Driving distance is almost always longer than crow-flies distance. Roads bend around hills, lakes, private land, and city blocks. The gap between the two numbers is called the detour percentage. It is smallest in flat places with a direct highway and largest in mountains, around big bays, or where roads are few. If two places are split by an ocean, there is no driving route at all, but the crow-flies distance still exists.
Bearing and Midpoint
The initial bearing is the compass direction you would face at the start to head straight toward the other point. It is given in degrees, where 0° is north, 90° is east, 180° is south, and 270° is west. A great circle's direction changes continually, so on a long trip the bearing slowly changes as you move along the curve, and the tool's figure is only the starting heading.1 The midpoint is the halfway spot along that great-circle path. It is handy when two people want to meet in the middle.
Common Uses
- Flights: airlines plan routes close to the great circle to save fuel and time.
- Shipping and delivery: zones and fees are often set by straight-line radius.
- School and job rules: many programs use a radius, like "within 25 miles," measured crow-flies.
- Real estate and search apps: "homes within 10 miles" usually means straight-line miles.
- Sports and hobbies: pilots, sailors, hams, and hikers use bearings and great-circle paths.
Distance Units
Distance is shown three ways. Miles are common in the United States and the United Kingdom. Kilometers are used in most other countries. Nautical miles are used in air and sea travel, and one nautical mile equals one minute of latitude.3 To convert: 1 kilometer = 0.621371 miles = 0.539957 nautical miles.
How Exact Is It?
The Haversine formula treats Earth as a perfect ball. Earth is really a little wider at the equator than pole to pole: its equatorial radius is 6,378.137 km and its polar radius 6,356.752 km.2 So results are slightly less exact than a method that uses Earth's true shape. For travel planning, radius rules, and general use, that is plenty close. Surveyors and navigators who need extra precision use Vincenty's formula, which works on an ellipsoid and was designed to be accurate over lines of any length, from a few centimetres to nearly 20,000 km.4