Tonga Government National Constitutional Monarchy, UN Member State (1999), Member of the Commonwealth (1970) Capital Nuku’alofa Population 99 780 Land area 749 km² Max height above sea level 1 033 m EEZ 659 558 km² GDP Year 2020 Currency Tongan Pa’anga (TOP) Languages English Tongan GDP per capita 5 081 USD Useful links Government of the Kingdom of Tonga The Kingdom of Tonga: the true South Pacific Demographic assessment of exploited coastal finfish species of Tongatapu, Tonga Pacific Community Membership 1983