At birth, the sex ratio in Tonga is 1.03 males/female; the ratio in the total population is 1.01 males/female. The 2006 Tongan census gave a fertility rate of 4.2 children/woman,although the 2011 World Factbook estimate is 3.55 children/woman.
Most of the Tongan population is Polynesian, with about 300 Europeans.
Christianity is the predominant religion in Tonga, with 37.3% of the population belonging to the Free Wesleyan Church, 16.8% Mormon, 15.6% Free Church of Tonga, and 11.3% Roman Catholic. Other Christian denominations make up 14%. Other religions make up 4% of the population, while 1% claim no affiliation.
The indigenous languages of the Kingdom of Tonga are the two Austronesian languages of Tongan and Niuafo'ou. Along with Tongan, English is also an official language.
98.5% of the Tongan population can read and write either English or Tongan, as of 1996.