VoyageDistance

Free Sea Distance & Transit Time Calculator: Port to Port & Multi-Leg Voyages

Calculate shipping distance and marine transit time between ports along real shipping routes — a free sea distance and transit time calculator for port-to-port and multi-leg voyages. Add as many stops as you need, no login or account required. It also works as a cargo ship distance calculator: pick a vessel type to estimate CO₂ emissions for bulk carriers, container ships, tankers, and more on the same route.

Routes are generated for visualization and voyage appraisal, not for actual ship navigation.

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Canals / straits the route may use

About the Constanta → Shanghai route

Sea route map from Constanta to Shanghai — 8270 nautical miles

The sea route from Constanta to Shanghai covers approximately 8270 nautical miles (15317 km). At a typical vessel speed of 14 knots, that's roughly 25 days at sea, not including port time, weather routing, or canal transit delays.

This route normally transits the Suez Canal. Routing around it instead adds about 6545 nautical miles and 19 extra days at 14 knots. See our Suez Canal vs. Cape of Good Hope comparison for why more ships are taking the longer route in 2026.

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Frequently asked questions

How is the Constanta to Shanghai transit time estimated?

VoyageDistance calculates the Constanta–Shanghai route along real shipping lanes and chokepoints, then divides the total distance by an assumed vessel speed (14 knots by default) to estimate transit time. Adjust the speed above to match your own vessel.

Can the Constanta to Shanghai route avoid the Suez Canal?

Yes — untick the Suez Canal checkbox above to see the alternative routing. Avoiding it adds about 6545 nautical miles and 19 days to this voyage at 14 knots.