Sea · sea or lake, by definition
Caspian Sea
Natural Earth’s outline of the Caspian Sea measures about 379,000 km² (146,000 mi²), the 15th largest of the 42 seas on sizeversus, and about the same size as Norway.
Whether the Caspian is called a sea or a lake depends on the definition used. Its name says sea and Natural Earth draws it with its marine areas, so Size Versus lists it with the seas, and also shows where it would stand among the lakes.
- Norway
- Caspian Sea
The numbers
- 379,000km²Area, measured146,000 mi² · Natural Earth outline
- 386,000km²Area, publishedWikidata · agrees within 2%
- 1,025mGreatest depthaverage about 207 m
- 78,700km³VolumeWikidata
The area is measured from the outline drawn above, on the WGS84 ellipsoid; the published figure is shown beside it, and a water body is kept only if the two are within 10%.
What the numbers say about the Caspian Sea
- The Arabian Sea, the largest of the 42 seas ranked on sizeversus, is 10.9× the size of the Caspian Sea; the Caspian Sea ranks 15th.
- The Caspian Sea sits between the Black Sea (422,000 km²) and the Yellow Sea (377,000 km²) in the ranking.
- Counted among the lakes it would be the largest of 104, 4.61× the size of Lake Superior.
- Counted as a country, the Caspian Sea would be larger than 150 of the 212 countries listed on sizeversus and would rank 63rd by area, between Norway (382,000 km²) and Japan (374,000 km²).
- It is larger than 47 of the 51 US states and districts (the biggest of them is New Mexico, 315,000 km²) and smaller than 4.
- It is larger than 23 of the 31 provinces and regions of China (the biggest of them is Guangxi, 237,000 km²) and smaller than 8.
- The closest US state is Montana (379,000 km²): the Caspian Sea is about the same size as Montana.
- Wikidata records a greatest depth of 1,025 m; with its volume that gives an average depth of about 207 m.
- Wikidata records a volume of 78,700 km³. Poured over Norway (382,000 km²), that water would stand 206 m deep.
- On a standard web map (Web Mercator), a place at 42°N is drawn about 1.8× too large in area, so the Caspian Sea looks bigger there than it is.
- Laid out flat, the Caspian Sea stretches about 1,170 km north to south and 611 km east to west.
- Wikidata’s published figure of 386,000 km² agrees with our measured 379,000 km², to within 2%.
About the same size as
Countries
On the shore
Natural Earth’s outlines of Kazakhstan, Russia, Turkmenistan, Azerbaijan and Iran lie within 25 km of the outline of the Caspian Sea. That is what its geometry says, and it is not a statement about who owns the water or where any border runs in it.
Names
- Caspian Seathe name in this page’s titlesource: Wikidata’s English label
Where the Caspian Sea ranks
The Caspian Sea is the 15th largest of the 42 seas on sizeversus, ranked by measured area.
Compare the Caspian Sea
Share this outline
Sources and method
- Outline
- Natural Earth, 1:10m Marine Areas (geography_marine_polys), public domain (Marine Areas (geography_marine_polys)). Natural Earth draws marine areas for labels and cuts them at named sub-areas; the outline is kept because its area matches the published one.
- Boundary
- A lake or a sea has no legal boundary of its own. The outline is a cartographic one, and the page says so by showing the measured area beside the published one.
- Area basis
- Measured outline: computed on the WGS84 ellipsoid from the full-detail outline and shown rounded. Published figure: Wikidata (CC0), fetched 2026-11-11. An outline is kept within 10% of the published figure and matched to other places automatically within 5%.
- Depth, volume, height
- As recorded in Wikidata; a volume that cannot be right for the area and depth is left out.
- Shore
- Countries whose Natural Earth outline contains or comes close to the water's outline; computed, not a statement of ownership.
- Drawing
- Each outline is projected with an equal-area projection centred on its own centroid, so areas stay true and two can be laid over each other.
- Data built
- 2026-11-11