Shalkar Lake is located in Shalkar District of Aktobe Region, in the southwestern part of Shalkar city. The lake is fed by the Kaulzhyr River, which originates in the Mugalzhar Mountains.

The lake lies at an elevation of 167 meters above sea level. Its surface area ranges from 5.65 to 7.9 km², with a length of 7 km and a maximum width of 1.8 km. The northern and northeastern shores are flat, while the remaining shores are predominantly steep.

Shalkar Lake shares the same basin with Eski Shalkar Lake. In the past, the two lakes formed a single body of brackish water. In 1937, the construction of a stone-and-concrete dam divided the original lake into two separate bodies of water: the freshwater Shalkar Lake in the northeast and the saline Eski Shalkar Lake in the southwest.