India's population as on 1 March 2011 stood at 1,210,193,422 (623.7 million males and 586.4 million females) in compared to a total of 1, 028, 737, 436 in the year 2001. In absolute term, the population of India has increased by more than 181 million during the decade 2001-2011.
The percentage decadal growth of population during 2001-2011 has registered the sharpest decline since independence. It declined from 23.87 per cent for 1981-1991 to 21. 54 per cent for the period 1991-2001, a decrease of 2.33 per cent. For 2001-2011, decadal growth has become 17.64 per cent, a further decrease of 3.90 percentage point.
Uttar Pradesh is the most populous state in the country with almost 200 million people. Sikkim is the least populous state with 6,07,688 people.
Source: India Book - A Reference Annual