Uzbekistan is 3.1 times larger than Tajikistan.
Area: 143,100 km2 World Factbook
Population: 8,051,512 (July 2014) World Factbook
Tajikistan, officially the Republic of Tajikistan, is a mountainous landlocked country in Central Asia. It is bordered by Afghanistan to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east. Mountains cover more than 90% of the country. Wikipedia
Area: 447,400 km2 World Factbook
Population: 28,929,716 (July 2014) World Factbook
Uzbekistan, officially the Republic of Uzbekistan, is a doubly landlocked country in Central Asia. It is a unitary, constitutional, presidential republic, comprising 12 provinces, 1 autonomous republic, and 1 independent city. Wikipedia