Zambia is 17% larger than S. Sudan.
Area: 644,329 km2 World Factbook
Population: 11,562,695 (July 2014) World Factbook
South Sudan, officially the Republic of South Sudan, is a landlocked country in northeastern Africa that gained its independence from Sudan in 2011. Its current capital is Juba, which is also its largest city. Wikipedia
Area: 752,618 km2 World Factbook
Population: 14,638,505 (July 2014) World Factbook
The Republic of Zambia is a landlocked country in Southern Africa, neighboring the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west. Wikipedia