| Călmuș | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Bacău County |
| Length: | 7km (04miles) |
| Source1 Coordinates: | 46.5439°N 26.5317°W |
| Source1 Elevation: | 440m (1,440feet) |
| Mouth: | Tazlăul Sărat |
| Mouth Coordinates: | 46.5269°N 26.6031°W |
| Mouth Elevation: | 325m (1,066feet) |
| Basin Size: | 13km2 |
The Călmuș (also: Calmus) is a left tributary of the river Tazlăul Sărat in Romania.[1] It discharges into the Tazlăul Sărat in Ardeoani. Its length is 7km (04miles) and its basin size is 13km2.