He passed away at his Baridhara home in Dhaka around 10pm on Saturday.
Ahmad was a two-time president of the Institute of Chartered Accountants of Bangladesh (ICAB).
He did his master's in commerce from the Dhaka University in 1954 and served as president of the South Asian Federation of Accountants.
Ahmad was Bangladesh's deputy prime minister from 1977 to 1982.
His cousin Rokon Uddin Mahmud said his first funeral prayer would be held at Gulshan Azad Mosque after Zuhr prayers on Sunday.
His body will be flown to Chittagong from there.
Ahmad's second Namaz-e-Janaza will be held at Jamiat'ul Falah grounds and third one at a school he had founded at Fatikchharhi's Daulatpur.
"He will be laid to rest at his family graveyard there," Mahmud told bdnews24.com.