Vietnam is 83% larger than Cambodia.
Area: 181,035 km2 World Factbook
Population: 15,458,332 (July 2014) World Factbook
Cambodia, officially known as the Kingdom of Cambodia and once known as the Khmer Empire, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia. Wikipedia
Area: 331,210 km2 World Factbook
Population: 93,421,835 (July 2014) World Factbook
Vietnam, officially the Socialist Republic of Vietnam, is the easternmost country on the Indochina Peninsula in Southeast Asia. With an estimated 90.0 million inhabitants as of 2013, it is the world's 13th-most-populous country, and the eighth-most-populous Asian country. Wikipedia