Great Circle Distance Calculator Nautical Miles
Calculate the shortest distance between two points on Earth using latitude and longitude. Results are provided in nautical miles, kilometers, and statute miles.
Great Circle Distance
How is great circle distance calculated?
Great circle distance is the shortest surface distance between two points on a sphere. Unlike a simple latitude or longitude distance calculation, it accounts for the Earth's curvature.
The calculator uses the haversine formula. Latitude and longitude are first converted from degrees to radians, then the angular distance between the two points is calculated.
$$a = \sin^2\left(\frac{\Delta\phi}{2}\right) + \cos(\phi_1)\cos(\phi_2)\sin^2\left(\frac{\Delta\lambda}{2}\right)$$
$$c = 2\arctan2\left(\sqrt{a},\sqrt{1-a}\right)$$
$$d = R \times c$$
- φ: Latitude in radians.
- λ: Longitude in radians.
- Δφ: Difference in latitude.
- Δλ: Difference in longitude.
- R: Earth's mean radius, approximately 3,440.065 nautical miles.
- d: Great circle distance.
Why is the result given in nautical miles?
Nautical miles are commonly used in marine navigation and aviation. One nautical mile corresponds to one minute of latitude along a meridian, making nautical miles especially useful for plotting distances on nautical charts.
Great circle distance vs. rhumb line distance
A great circle route represents the shortest path between two points on a spherical Earth. A rhumb line, also called a loxodrome, follows a constant compass bearing. For long ocean passages, the great circle route is generally shorter, while a rhumb line can be easier to follow because the heading remains constant.
Is this calculator accurate for navigation?
This calculator is suitable for estimating geographic distance between coordinates. It models the Earth as a sphere, so it should not be treated as a replacement for professional navigation software when highly precise marine navigation is required.
What is the difference between nautical miles and miles?
One nautical mile is equal to approximately 1.15078 statute miles, or approximately 1.852 kilometers.