After the 2011 Census, Bihar was the third most populous state of India with total population of 104,099,452 (54,278,157 male and 49,821,295 female). Nearly 89 % of Bihar 's population lived in rural areas. The density was 1,106. The sex ratio was 918 females per 1000 males. Almost 58 % of Bihar 's population was below 25 years age, which is the highest in India. Most of Bihar 's population belongs to Indo - Aryan - speaking ethnic groups along with few Dravidian - speaking and Austroasiatic - speaking people mostly in Chhotanagpur Plateau (now part of Jharkhand). It also attracted Punjabi Hindu refugees during the Partition of British India in 1947. Bihar has a total literacy rate of 63.82 % (75.7 % for males and 53 % for females), recording a growth of 20 % in female literacy over the period of a decade.
according to 2011 census per square kilometre density of population in bihar
1,106