What is a nautical mile?

A nautical mile (NM) is exactly 1,852 meters (1.852 km). It is defined as one arc-minute of latitude along any meridian, making it naturally suited to navigation and chart work.

What is the Haversine formula?

The Haversine formula calculates the great-circle distance between two points on a sphere given their latitudes and longitudes. It accounts for Earth's curvature and is accurate to within 0.3% for most practical distances.

Is this the same as rhumb-line distance?

No. This tool computes the great-circle (orthodrome) distance, which is the shortest path over the Earth's surface. A rhumb line (loxodrome) follows a constant compass bearing and is generally longer except along meridians or the equator.

How accurate is the result?

The Haversine formula treats Earth as a perfect sphere. For most navigation purposes the error is less than 0.5%. For extreme precision over long distances, geodetic formulas such as Vincenty's are used, but the difference rarely exceeds a few kilometers.

What coordinate format should I use?

Enter decimal degrees (e.g., -33.8688 for south). Positive values are North/East, negative are South/West. Latitude ranges from -90 to 90, longitude from -180 to 180.

What does the bearing represent?

The initial bearing is the compass heading (0–360°) you would follow from the origin to reach the destination along the great-circle route. Due to Earth's curvature this heading changes as you travel, unlike a rhumb line.

Nautical Distance Calculator

Name: Nautical Distance Calculator
Availability: InStock
Author: Nham Vu

Enter two sets of latitude/longitude coordinates to instantly get the great-circle distance in nautical miles, kilometers, and statute miles.

Origin

Latitude

Longitude

Decimal degrees. Positive = N/E, negative = S/W.

Destination

Latitude

Longitude

Quick presets:

Enter coordinates or choose a preset, then click Calculate.

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Summary

Enter two sets of latitude/longitude coordinates to instantly get the great-circle distance in nautical miles, kilometers, and statute miles.

How it works

Enter the latitude and longitude of your starting point (Origin).
Enter the latitude and longitude of your destination point.
Use decimal degrees (e.g., 40.7128) or switch to DMS format using the toggle.
The tool applies the Haversine formula to compute the great-circle distance.
Results appear instantly in nautical miles, kilometers, and statute miles.
The initial bearing (compass heading) from origin to destination is also shown.

Use cases

Plan offshore sailing routes and estimate voyage time.
Calculate flight distances for aviation route planning.
Determine sea distances for shipping and cargo logistics.
Verify chart plotter readings with an independent calculation.
Estimate fuel requirements for marine or aerial journeys.
Cross-reference GPS coordinates in navigation training exercises.
Compare distances for search-and-rescue planning.
Compute leg distances for a multi-waypoint passage plan.

Frequently Asked Questions

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Last updated: 2026-05-23 · Reviewed by Nham Vu