Great circle vs rhumb line explorer

Choose two endpoints

Results update instantly. Use the button only if you want a shareable URL.

Start point input

Use a city Drop a pin on the map

Start point

GeoNames-derived reference set with 6077 cities. Filter first, then choose the exact city.

The selected city becomes the start point and shareable URL value.

Start point map pin

Start point 51.5074°, -0.1278°

Latitude

Longitude

Use map mode when your route starts from an arbitrary sea lane, island, or non-city point.

Map base: World map configurable.svg on Wikimedia Commons, a CC0 Robinson projection centered at 10°E.

End point input

Use a city Drop a pin on the map

End point

Pick the route destination from the same city dataset, or switch to a custom map pin below.

The selected city becomes the destination and shareable URL value.

End point map pin

End point 40.7128°, -74.006°

Latitude

Longitude

Map mode is useful for routes that end at a waypoint, offshore platform, or general region instead of a city center.

Map base: World map configurable.svg on Wikimedia Commons, a CC0 Robinson projection centered at 10°E.

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Why this page exists

Search results for great circle versus rhumb line are often split between nautical math references and shallow explainers that never show the real tradeoff. People usually want the practical version: which route is shorter, what heading would I hold, and why does the line look wrong on a world map?

This page answers that with two route models side by side. It treats route geometry as a visual problem instead of only a formula problem.

Useful search intents: great circle vs rhumb line, loxodrome vs great circle, and why flight paths curve on a map.

Good for

• Explaining why long-haul flights arc toward a pole even when the route feels visually indirect
• Checking how much longer a constant-heading rhumb line is on a real city-to-city route
• Teaching the link between Mercator charts, loxodromes, and shortest-path navigation

Important limitation

This compares idealized routes on a spherical Earth. It does not account for winds, restricted airspace, currents, coastlines, fuel stops, or airline and shipping operations.

Read the launch note for this explorer.