World Port Distance Calculator

Great Circle Distance Formula:

\[ Distance = \arccos(\sin(lat1) \times \sin(lat2) + \cos(lat1) \times \cos(lat2) \times \cos(lon2-lon1)) \times 3440 \]

Latitude of Port 1:

degrees

Longitude of Port 1:

degrees

Latitude of Port 2:

degrees

Longitude of Port 2:

degrees

Distance Between Ports:

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1. What is the Great Circle Distance?

The Great Circle Distance is the shortest distance between two points on the surface of a sphere, following the curvature of the Earth. This calculator provides the distance in nautical miles between any two ports worldwide using their latitude and longitude coordinates.

2. How Does the Calculator Work?

The calculator uses the Great Circle Distance formula:

\[ Distance = \arccos(\sin(lat1) \times \sin(lat2) + \cos(lat1) \times \cos(lat2) \times \cos(lon2-lon1)) \times 3440 \]

Where:

\( lat1, lon1 \) — Latitude and longitude of first port (degrees)
\( lat2, lon2 \) — Latitude and longitude of second port (degrees)
3440 — Radius of Earth in nautical miles (mean value)

Explanation: The formula calculates the central angle between two points on a sphere and multiplies it by the Earth's radius to get the distance.

3. Importance of Port Distance Calculation

Details: Accurate distance calculation between ports is essential for voyage planning, fuel estimation, shipping logistics, and maritime navigation.

4. Using the Calculator

Tips: Enter latitude (-90 to 90 degrees) and longitude (-180 to 180 degrees) for both ports. Positive values are North/East, negative values are South/West.

5. Frequently Asked Questions (FAQ)

Q1: Why use nautical miles instead of kilometers?
A: Nautical miles are the standard unit of measurement in maritime and aviation navigation (1 nautical mile = 1.852 km).

Q2: How accurate is this calculation?
A: It provides the theoretical shortest distance. Actual sailing distances may differ due to land masses, currents, or shipping lanes.

Q3: Where can I find port coordinates?
A: Most port authorities provide coordinates, or you can use services like World Port Index or marine charts.

Q4: Does this account for Earth's oblateness?
A: This uses a spherical Earth model. For extreme precision, ellipsoidal models like Vincenty's formula would be needed.

Q5: Can I use this for air distance calculations?
A: Yes, the same formula works for great circle distances in aviation, though altitudes are not considered.