The Flag of Kaluga is the official heraldic symbol representing the federal subject of the Russian Federation known as the Kaluga Oblast. The flag was officially adopted on July 23, 1997. The design consists of two horizontal rectangles divided equally. The upper rectangle, taking up about two-thirds of the total flag area, is divided diagonally from top left to bottom right with a white, isosceles triangle pointing towards the hoist side. This triangle represents the Kaluga Coat of Arms, which features three golden crowns on a blue field. The lower rectangle is green, symbolizing agriculture and nature. The flag's proportions are 2:3. The Flag of Kaluga embodies the region's historical and cultural significance within Russia.