Koirganwan is a village in Narkatiaganj tehsil in district of Pashchim Champaran, Bihar, India. As per the data provided by Census of India in 2011, total population of Koirganwan was 1,699 which includes 861 males and 838 females. Koirganwan covers 185.12 ha area. Pincode of Koirganwan is N/A.