Indonesia is a highly diverse country, both ethnically and linguistically. The country's population reached 270.20 million according to the 2020 national census, up from 237.64 million in 2010. As of mid-2025, the official estimate stood at 284.44 million, reflecting an annual growth rate of 1.11%. It remains the fourth most populous country in the world. Java, excluding Madura, is home to approximately 54.4% of the national population, making it the most densely populated island globally.
Despite a fairly effective family planning program that has been in place since 1967, Indonesia's average population growth per year was over 1.1% for the decade ending in 2020, nearly having 13% population growth for that decade. At this rate, Indonesia's population is no longer projected to surpass the population of the United States (whose population is increasing at a faster rate), and it is itself projected by the United Nations (UN) to be overtaken in population by Nigeria and by Pakistan by 2040. Indonesia has a relatively young population compared to many Western countries, although it is gradually aging due to declining birth rates and rising life expectancy. As of 2017, the median age stood at 30.2 years.
The country is among the most ethnically and linguistically diverse in the world, home to over 600 ethnic groups and more than 700 languages. Since gaining independence, Indonesian has served as the national language and is widely used in education, government, business, and formal communication. However, most Indonesians grow up speaking a regional language as their mother tongue, using Indonesian primarily as a lingua franca for interethnic interaction. Major regional languages include Javanese, Sundanese, Minangkabau, Buginese, Balinese, and Batak, among many others. The Javanese, who make up about 40% of the population, have historically held significant political influence, with every president since independence having at least partial or full Javanese ancestry.
Source: Our World in Data, Statistics Indonesia, Wertheim (1959), Geografi dan Kependudukan (1976), Widjojo Nitisastro (2006)
Source: Population Census 2010, except for final column, taken from Population Census 2020.
Note: <sup>(a)</sup> North Kalimantan province was created in 2012 (by separation from East Kalimantan province); the 2010 total figures given are those for the provinces as they were following that splitting (Urban % and Total Fertility Rate columns unadjusted).
Population Estimates by Sex and Age Group (01.VII.2020) (Data are based on the publication: "Indonesia Population Projection 2015-2045"):
Source: UN DESA, World Population Prospects, 2022
Total Fertility Rate (TFR) (Wanted Fertility Rate) and Crude Birth Rate (CBR):
Total fertility rate (TFR) and population over age 60 by region as of 2010:
<small>Note: No data is available for 2017.</small>
Indonesia is a country of great ethnic diversity, with approximately 600 distinct indigenous ethnic groups living side by side across more than 17,000 islands. The majority of Indonesia's population is descended from Austronesian peoples who are concentrated in western and central Indonesia, which is part of the Asian continent. Another large group is the Melanesian peoples, who inhabit the eastern part of Indonesia (the Maluku Islands, Western New Guinea, and the East Nusa Tenggara) in Oceania.
The Javanese are the largest ethnic group, accounting for 40.2% of the population and are culturally, economically, and politically dominant. The Javanese are concentrated in Java, the most populous island, especially in the central and eastern parts, and also in significant numbers in most provinces due to extensive migration throughout the archipelago. The Sundanese are the next largest group (15.4%), followed by the Malays, Batak, Madurese, Betawi, Minangkabau, and Bugis. A sense of Indonesian nationalism is present along with strong ethnic and regional identities.
Indonesian is the official and national language of Indonesia, widely spoken by over 97% of the population. However, Indonesia is a highly multilingual country. According to Ethnologue, there are currently 737 regional languages spoken across the Indonesian archipelago. This extensive linguistic diversity accounts for about 10% of the worldâÂÂs total languages, making Indonesia the second most linguistically diverse country in the world. The majority of these languages belong to the Austronesian language family, which is prevalent in the western and central regions of Indonesia, including languages such as Acehnese, Batak, Sundanese, Balinese, Banjarese and Buginese. In contrast, the eastern regions, particularly Papua and the Maluku Islands, are home to over 270 Papuan languages, which are distinct from the Austronesian language family and represent a unique linguistic heritage. The most widely spoken language as a mother tongue is Javanese, spoken by over 80 million speakers, mainly in central and east Java, but also on many other islands due to migration.
Indonesia is the world's most populous Muslim-majority nation; based on civil registration data in 2024 from Ministry of Home Affairs, 87.09% of Indonesians are Muslims, 10.45% Christians (7.38% Protestants, 3.07% Roman Catholic), 1.67% Hindu, 0.71% Buddhists, 0.03% Confucians and 0.04% Folk and other faiths. Most Indonesian Hindus are Balinese and most Buddhists in modern-day Indonesia are Chinese.