Machhar Ganwan is a village in Kotwa tehsil in district of Purba Champaran, Bihar, India. As per the data provided by Census of India in 2011, total population of Machhar Ganwan was 5,666 which includes 3,000 males and 2,666 females. Machhar Ganwan covers 543.9 ha area. Pincode of Machhar Ganwan is 845417.