S. Sudan is 2.7 times larger than Uganda.
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: 241,038 km2 World Factbook
Population: 35,918,915 (July 2014) World Factbook
Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by Tanzania. Wikipedia