Mauritania is 3.8 times larger than Burkina Faso.
Area: 274,200 km2 World Factbook
Population: 18,365,123 (July 2014) World Factbook
Burkina Faso, also known by its short-form name Burkina, is a landlocked country in West Africa around 274,200 square kilometres in size. It is surrounded by six countries: Mali to the north; Niger to the east; Benin to the southeast; Togo and Ghana to the south; and Ivory Coast to the southwest. Wikipedia
Area: 1,030,700 km2 World Factbook
Population: 3,516,806 (July 2014) World Factbook
Mauritania, officially the Islamic Republic of Mauritania, is a country in the Maghreb region of western North Africa. Wikipedia