Raychaudhuri was born in a Baidya family coming from Barisal (now in Bangladesh) on 14 September 1923, to Surabala and Sureshchandra Raychaudhuri. He was just a child when the family migrated to Kolkata. He had his early education in Tirthapati Institution and later completed matriculation from Hindu School, Kolkata. In a documentary film made just before his death in 2005, AKR reveals that he was extremely passionate about mathematics right from his schooldays and solving problems would give him immense pleasure. He recalls in the documentary how his grade 9th teacher credited him for discovering a simpler solution for a mathematics problem. May be the fact that his father was a mathematics teacher in a school also inspired him. At the same time, as his father was not so 'successful' so to say, he was discouraged to take up mathematics, his first choice, as honours subject in college.