Fratrovci is located in the municipality Bosiljevo, in Karlovac County at an elevation of 140 meters above sea level and it covers the area of 4.57 km² (1.76 sq. miles). According to the 2011 census report, there were 31 inhabitants. It is predominantly populated by Croats (94%), but also Slovenes (6%). Nearby places: Zdihovo, Pribanjci, Kasuni, Bosanci, Rim, Sela Bosiljevska, Liplje, Klanac, Jančani and Plešivica.