OceanCalc

Great Circle Distance Calculator — Meters

Compute the shortest distance between two locations on Earth using latitude and longitude. Results in nautical miles and kilometers.

Last updated: March 28, 2026

Author: OceanCalc Editorial Team · Publisher: Albor Digital LLC

Page focus

When you want meter-centric outputs from the Great Circle Distance Calculator, work in the fields above and cross-check against metric charts or soundings.

Great Circle Distance Calculator

Result

Distance (nautical miles)

3007.7

Distance (km)

5570.2

Formula

Haversine: d = 2R × asin(√(sin²(Δlat÷2) + cos(lat1)×cos(lat2)×sin²(Δlon÷2)))

Overview

The Great Circle Distance Calculator gives you precise nautical results from familiar formulas, with an interface suited to deck and chart-table use.

How to use

To use the Great Circle Distance Calculator, enter your values in the fields above. Results update as you adjust numbers, so you can compare scenarios without leaving the page.

Formula

The relationship behind this tool is: Haversine: d = 2R × asin(√(sin²(Δlat/2) + cos(lat1)×cos(lat2)×sin²(Δlon/2)))

Haversine formula: a = sin²(Δlat/2) + cos(lat₁)×cos(lat₂)×sin²(Δlon/2); c = 2×atan2(√a, √(1−a)); d = R × c. R ≈ 3,440.065 nautical miles (Earth radius).

A great circle is any circle on Earth's surface whose center is the planet's center. The shortest route between two points lies along the unique great circle that passes through both.

Practical use cases

Typical uses for the Great Circle Distance Calculator include passage planning, briefing crew, converting instrument readouts to chart units, and double-checking mental math when fatigue or weather make errors more likely.

Tips for accuracy

  • Confirm that the units you enter match your chart, GPS, or instrument readout before relying on the Great Circle Distance Calculator.
  • In rough weather or poor visibility, cross-check important results with a second method or a crew member.
  • Treat simplified models (wave height, radar horizon, etc.) as estimates—real conditions vary with fetch, refraction, and equipment.

Practical examples

  • New York to London: ~3,076 nm (~5,697 km)
  • 1° of latitude ≈ 60 nm (along a meridian)
  • Equator: 1° longitude = 60 nm; at 60°N, 1° longitude ≈ 30 nm

Frequently Asked Questions

  • What is great circle distance?

    The great circle distance is the shortest path between two points on the surface of a sphere (Earth). It follows the arc of a circle whose center is the Earth's center. Sailing or flying great circle routes minimizes distance.

  • How is great circle distance calculated?

    The haversine formula uses the latitudes and longitudes of both points to compute the central angle between them, then multiplies by Earth's radius (in nautical miles, about 3,440) to get distance.

  • Why use nautical miles for great circle?

    One nautical mile equals one minute of latitude, so great circle distance in nm relates directly to angular distance. For example, 60 nm is 1° of arc along a great circle.

  • How accurate is this calculator?

    This calculator uses standard maritime formulas and practical approximations where noted. It is suitable for planning and cross-checks; always verify safety-critical decisions with official references and local conditions.

  • Can I use this on mobile?

    Yes. OceanCalc tools are responsive and work on phones and tablets for quick checks on deck or in the cockpit.

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Results are estimates for educational purposes only and should not be used for real navigation decisions.

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