Zambia is 3.8 times larger than Senegal.
Area: 196,722 km2 World Factbook
Population: 13,635,927 (July 2014) World Factbook
Senegal, officially the Republic of Senegal, is a country in West Africa. It is the westernmost country in the mainland of the Old World or Eurafrasia and owes its name to the Sénégal River that borders it to the east and north. 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