| Official Name: | Kalmahr |
| Native Name: | كلمهر |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Mazandaran |
| Subdivision Type2: | County |
| Subdivision Name2: | Sari |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Rudpey-ye Shomali |
| Population As Of: | 2006 |
| Population Total: | 452 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 36.7333°N 53.05°W |
Kalmahr (Persian: كلمهر’ also known as Kalmar) is a village in Rudpey-ye Shomali Rural District, in the Central District of Sari County, Mazandaran Province, Iran. At the 2006 census, its population was 452, in 119 families.