Thailand is 66% larger than Oman.
Area: 309,500 km2 World Factbook
Population: 3,219,775 (July 2014) World Factbook
Oman, officially called the Sultanate of Oman, is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It has a strategically important position at the mouth of the Persian Gulf. Wikipedia
Area: 513,120 km2 World Factbook
Population: 67,741,401 (July 2014) World Factbook
Thailand, officially the Kingdom of Thailand, formerly known as Siam, is a country at the centre of the Indochina peninsula in Southeast Asia. Wikipedia