PPolySim OS

Rhumb Line vs Great Circle

Steer a constant compass heading and you follow a rhumb line — simple but longer. Take the shortest path and you follow a great circle — but your heading keeps changing.

Rhumb Line vs Great CircleLive

Controls

Presets

A rhumb line holds a constant compass bearing — easy to steer, and a straight line on a Mercator map, but longer. A great circle is the shortest route but its bearing changes continuously, tracing a curve on the map. Ships and planes crossing oceans follow the great circle, adjusting heading along the way to save fuel and time.

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Data Inspector

Great-circle dist9272 km
Rhumb-line dist11022 km
Extra by rhumb1750 km

Governing equation

Reading this result: Steering the constant-bearing rhumb line adds about 1750 km (18.9%) over the great circle — the penalty grows with higher latitudes and a wider longitude gap.

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How it works

A rhumb line (loxodrome) crosses every meridian at the same angle, appearing as a straight line on a Mercator chart and easy to steer, but it is not the shortest route. A great circle is the shortest path yet curves on the map and demands continuous heading changes. Long-haul ships and aircraft fly great-circle routes, breaking them into rhumb-line segments in practice.

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The math, the assumptions, real-world uses, or a code translation — explained for this exact simulation.

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Frequently asked questions

Is this rhumb line great circle tool really free?
Yes. Rhumb Line vs Great Circle runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.