The leader of opposition would traverse roughly 5,800 km across 10 states - Gujarat, Maharashtra, Karnataka, Andhra Pradesh, Chattisgarh, Madhya Pradesh, Rajasthan, Uttar Pradesh, Haryana and Delhi, senior party leader N Venkaiah Naidu told reporters in New Delhi.
Advani would cover the yatra in roughly 26 days with breaks in between to campaign in West Bengal, Tamil Nadu and Pondicherry.
Both leaders would skip the five poll-bound states and the northeast, Naidu said.
Singh would cover approximately 5,000 km over 24 days in 22 states, including Orissa, Chhattisgarh, Jharkhand, Bihar, Uttar Pradesh, Uttaranchal, Himachal Pradesh, Jammu and Kashmir, Punjab, Rajasthan and Haryana.
The twin yatra, announced in the wake of the Varanasi bomb blasts, would begin on the party's foundation day on April 6 and conclude on May 10, the 149th anniversary of India's First War of Independence.
The details of the yatra, aimed at "opposing the divisive policies of United Progressive Alliance and its soft approach against terrorism," were finalised at a meeting of state party presidents and general secretary organisation chaired by Rajnath Singh.
The overall coordination of the yatra has been entrusted to Naidu. Party general secretary Ananth Kumar would be incharge of Advani's yatra while party secretary Vijay Goel would be incharge of Singh's yatra.