Gahna is a village in Maunath Bhanjan tehsil in district of Mau, Uttar Pradesh, India. As per the data provided by Census of India in 2011, total population of Gahna was 3,047 which includes 1,491 males and 1,556 females. Gahna covers 998.45 ha area. Pincode of Gahna is 221705.