Neptune Atlas
Houston to Ulsan by sea: 9,656 nautical miles
Houston to Ulsan by sea is 9,656 nautical miles (17,883 km) through the Panama Canal. Without the Panama Canal it is 14,302 nautical miles through the Suez Canal, 4,646 longer. The distance is the same in both directions, so this is also the distance from Ulsan to Houston. Ships on this route often carry crude oil.
| Route | Nautical miles | Days at sea at | |||
|---|---|---|---|---|---|
| 10 knots | 12 knots | 14 knots | 16 knots | ||
| Through the Panama Canal | 9,656 | 40.2 | 33.5 | 28.7 | 25.1 |
| Through the Suez Canal, without the Panama Canal | 14,302 | 59.6 | 49.7 | 42.6 | 37.2 |
Days are time under way at a steady speed. They leave out waiting, time in port and bad weather. The Panama Canal adds about 1.17 days for the transit and the wait.
Without the Panama Canal the voyage is 4,646 nm longer, which is 16.1 more days at sea at 12 knots.
- Canals
- Panama Canal
- Canal time
- 1.17 days
- Inside emission areas
- 356 nm
- Straight line
- 6,146 nm
Emission control areas
356 nm of this route, 4 per cent, is inside an emission control area (ECA): North American ECA, Atlantic and Gulf of Mexico, 356 nm. An ECA is a sea area where a ship must burn fuel with no more than 0.10 per cent sulphur, or clean its exhaust. Either costs more than sailing on ordinary fuel.
The two ports
- Houston, United States. UN/LOCODE USHOU, at 29.75 N, 95.35 W.
- Ulsan, South Korea. UN/LOCODE KRUSN, at 35.53 N, 129.32 E.
A UN/LOCODE is the United Nations code for a port. The straight line above is the great circle, the shortest line over the globe, which crosses land.
How this was worked out
Computed on 13 October 2026 by the sea router behind the Neptune Atlas voyage estimator. It searches a grid of navigable water built from public sea depth data, so the track goes round headlands and through straits. No draft limit was set and no area was avoided. Distance tables differ by a few per cent, because each one picks its own point for a port and its own track through straits. Use it for planning, not in place of a chart.
Open this route in the free calculator Change the speed, set a sea margin or close a canal. No account is needed.
Related routes
Other routes at Houston
- Houston to Rotterdam5,054 nm
Other routes at Ulsan
- Kuwait to Ulsan6,483 nm
Guides that go with this route
- Emission control areas: where they are and what fuel a ship must burn inside them.
- Bunkers and fuel grades: what a ship burns on a passage like this one.
- Laytime and demurrage: the time allowed in port once the ship arrives.