Gamharia Birnagar is a village in Sikta tehsil in district of Pashchim Champaran, Bihar, India. As per the data provided by Census of India in 2011, total population of Gamharia Birnagar was 3,170 which includes 1,650 males and 1,520 females. Gamharia Birnagar covers 645.2 ha area. Pincode of Gamharia Birnagar is 845307.