Radmanovac is located in the municipality Vojnić, in Karlovac County at an elevation of 140 meters above sea level and it covers the area of 2.50 km² (0.97 sq. miles). According to the 2011 census report, there were 31 inhabitants. It is predominantly populated by Serbs (94%), but also Croats (6%). Nearby places: Jurga, Vojnić, Kupljensko, Kolarić, Krivaja Vojnićka, Radonja, Poljana Vojnićka, Vojišnica, Kokirevo and Knežević Kosa.