| Călmățui River | |
| River | |
| Countries | Romania |
|---|---|
| Counties | Buzău, Brăila |
| Tributaries | |
| - left | Negreasca, Rușavăț, Batogu |
| - right | Strâmbeanu, Puturosu |
| Towns | Smeeni, Însurăței |
| Source | |
| - location | South of Buzău |
| Mouth | Danube |
| - location | Berteștii de Jos |
| - coordinates | 44°49′52″N 27°49′38″E / 44.83111°N 27.82722°ECoordinates: 44°49′52″N 27°49′38″E / 44.83111°N 27.82722°E |
| Length | 145 km (90 mi) |
| Basin | 820 km2 (317 sq mi) |
| Progression | Danube→ Black Sea |
The Călmățui River is a tributary of the Danube in Romania. Its source is a few km southwest of Buzău. It flows generally eastwards and flows into the Danube at Berteștii de Jos.