Sources disagree as to the current population of Eritrea, with some proposing numbers as low as 3.6 million and others as high as 6.7 million. Eritrea has never conducted an official government census.

The nation has nine recognized ethnic groups. Of these, the largest is the Tigrinya, who make up around 50% of the population; the Tigre people, who also speak Semitic languages, constitute around 30% of residents. Most of the rest of the population belong to other Afro-Asiatic-speaking communities of the Cushitic branch. Additionally, there are a number of Nilo-Saharan-speaking ethnic minorities and other smaller groups.

The two most followed religions are Christianity (47%-63% of the total population) and Islam (37%-52%).

Population Sources disagree as to the current population of Eritrea, with UN DESA proposing a low estimate of 3.6 million for 2021 and the Common Market for Eastern and Southern Africa proposing a high estimate of 6.7 million for 2019. Eritrea has never conducted an official government census. In its 2019 data release, UN DESA described why its estimate was much lower than earlier estimates, stating, "The decrease is due to the availability of new official population estimates for several years (population count in 2000, official estimates up to 2018) that contribute to lower the size of the population in the recent years, as well as to revised past estimates since 1950."

In the 2010s, worsening conditions fueled migration pressure, with Eritreans trying to reach Europe illegally.Why they leave -- Eritreans are taking to the seas because of worsening conditions at home 12 October 2013. "Some 30,000 people reached Italy illegally in boats in the first nine months of 2013, three times as many as in the whole of 2012, according to Frontex, [...] the largest batch came from Eritrea, a country that has supposedly been at peace for the past 13 years." Emigration has left Eritrea ‘desolate’, say bishops, Catholic Herald, 6 September 2014.Bilateral Estimates of Migrant Stocks in 2010 estimates 942,000 emigrants, of whom 450,000 migrated to Sudan and 290,000 to Ethiopia. Cf. the World' Bank's Migration and Remittances Factbook 2011. The UN Department of Economic and Social Affairs expects Eritrean population growth to accelerate to 1.8% per year from 2020 to 2030, vs. 1.1% per year from 2010 to 2020.

The proportion of children below the age of 15 in 2020 was 41.1%, 54.3% were between 15 and 65 years of age, while 4.5% were 65 or older.

Population aged 0–14 (%)Population aged 15–64 (%)Population aged 65+ (%) 195045.351.63.0 196043.453.92.7 197044.153.42.5 198044.353.12.6 199045.252.12.7 200045.750.43.8 201039.556.54.0 202041.154.34.5

Population Estimates by Sex and Age Group (1 July 2020) (Estimates based on the 2000 quick population count results and 1995, 2002 and 2010 Eritrea Demographic and Health Surveys.): Age groupMaleFemaleTotal% Total 1 704 531 1 760 057 3 464 588 100 0–4 258 209 260 452 518 661 14.97 5–9 226 081 229 410 455 492 13.15 10–14 189 259 192 799 382 058 11.03 15–19 156 082 159 332 315 413 9.10 20–24 141 888 134 220 276 108 7.97 25–29 166 664 158 295 324 959 9.38 30–34 139 275 141 835 281 110 9.11 35–39 103 079 103 347 206 427 5.96 40–44 62 197 76 107 138 304 3.99 45–49 60 159 77 960 138 119 3.99 50–54 47 632 55 264 102 896 2.97 55–59 39 491 50 117 89 607 2.59 60–64 34 801 35 259 70 060 2.02 65–69 28 019 28 134 56 153 1.62 70–74 22 886 24 318 47 204 1.36 75–79 14 576 18 574 33 150 0.96 80–84 8 912 10 116 19 028 0.55 85+ 5 323 4 519 9 842 0.28Age groupMaleFemaleTotalPercent 0–14 673 549 682 661 1 356 210 39.14 15–64 951 266 991 735 1 943 001 56.08 65+ 79 716 85 661 165 377 4.77

Vital statistics

Demographic and Health Surveys The United Nations Department of Economic and Social Affairs (UN DESA) Population Division published its UN DESA 2019 Revision (World Population Prospects 2019) data release based on several data samples, including the 1995 and 2002 Demographic and Health Surveys (1995 DHS, 2002 DHS) and the 2010 Population and Health Survey (2010 PHS), since a full census had not been carried out in Eritrea .

The 1995 DHS survey was carried out in Eritrea by the Eritrean National Statistics Office (NSO) and Macro International Inc., collecting data by interviewing 5,054 women aged 15–49 and 1,114 men aged 15–59, chosen to be a statistically representative sample, from September 1995 to January 1996.

The 2002 DHS survey was carried out by the NSO (renamed as the National Statistics and Evaluation Office), with support from the United States Agency for International Development (USAID) and ORC Macro, collecting data with interviews of 8,754 women in Eritrea in the 15–49 age range, in what was considered to be a statistically representative sample of the full population. Key findings of the survey included a drop from 1995 to 2002 of fertility from 6.1 to 4.8 children per woman; improved knowledge of contraception; a drop in post-neonatal mortality; improved antenatal care; a doubling of the full vaccination rate for 12–23 month old babies from 41 to 76 percent; 38 percent of children under five years old were chronically malnourished or stunted; and near universal knowledge of HIV and AIDS.

In 2010, the NSO, supported by the Fafo Institute for Applied International Studies, published a Population and Health Survey (EPHS2010), based on a survey covering 34,423 households by choosing 900 areas around Eritrea, 525 rural and 375 urban, and randomly selecting 40 households in each cluster. Interviews aimed to include all women aged 15–49 and men aged 15–59 who were either residents or visitors in any selected household on the night preceding the interview. Key findings compared to the 1995 DHS survey included a decrease in early childhood mortality, increased children's vaccination, decreased maternal death, and a "wide gap between knowledge and use of family planning".

Fertility and mortality PeriodLive births per 5 yearsDeaths per 5 yearsNatural change per 5 yearsCBR*CDR*NC*TFR*IMR* 1950–1955 204 000 128 000 76 000 47.5 29.7 17.7 6.96 199 1955–1960 233 000 128 000 105 00048.8 26.8 22.0 6.96 181 1960–1965 261 000 127 000 134 00048.4 23.6 24.8 6.82160 1965–1970 291 000 133 000 158 00047.4 21.7 25.7 6.70148 1970–1975 324 000 140 000 184 00046.0 19.8 26.26.62140 1975–1980 366 000 148 000 218 00045.3 18.3 27.9 6.62 132 1980–1985 422 000 161 000 261 00045.2 17.3 27.7 6.70 121 1985–1990 469 000 174 000 295 00044.0 16.4 23.3 6.6 112 1990–1995 428 000 168 000 260 00038.4 15.1 19.4 6.394.4 1995–2000 359 000 140 000 219 00031.9 12.5 24.0 5.671.1 2000–2005 442 000 135 000 307 00034.6 10.6 28.3 5.159.4 2005–2010 564 000 140 000 424 00037.6 9.4 28.3 4.851.6 2010–2015 552 000 134 000 418 00033.9 8.2 25.7 4.3545.0 2015–2020 528 000 125 000 403 00030.6 7.2 23.4 4.1 34.7 * Values per year: CBR = crude birth rate (per 1000); CDR = crude death rate (per 1000); NC = natural change (per 1000); IMR = infant mortality rate per 1000 births; TFR = total fertility rate (number of children per woman)

Urban/rural and geographical distribution Total Fertility Rate (TFR) (Wanted Fertility Rate) and Crude Birth Rate (CBR) (1995 DHS, Table 3.1; 2002 DHS, Table 4.1;) Year Total Urban Rural CBR TFR CBR TFR CBR TFR 1995 37.5 6.10 29.3 4.23 40.3 6.99 2002 32 4.8 28 3.5 35 5.7

Fertility geographical distribution as of 2010 (PHS, Table 4–2):

Zoba Total fertility rate Mean number of children ever born to women age 40–49 Percentage of women age 15-49 currently pregnant Debubawi Keih Bahri 4.2 5.4 7.6 Maekel 3.4 4.1 5.5 Semenawi Keih Bahri 5.4 5.9 8.1 Anseba 5.7 6.3 8.2 Gash-Barka 5.4 5.6 8.0 Debub 5.0 6.0 7.9

Life expectancy PeriodLife expectancy in Years1950–195534.081955–1960 36.681960–1965 40.081965–1970 42.151970–1975 44.111975–1980 45.911980–1985 47.331985–1990 48.691990–1995 50.771995–2000 53.972000–2005 56.702005–2010 60.712010–2015 63.422015–2020 65.74

Migration

In 2015, there was a major outflow of emigrants from Eritrea. The Guardian attributed the emigration to Eritrea being "a totalitarian state where most citizens fear arrest at any moment and dare not speak to their neighbours, gather in groups or linger long outside their homes", with a major factor being the conditions and long durations of conscription in the Eritrean Army. At the end of 2018, the United Nations High Commissioner for Refugees (UNHCR) estimated that about 507,300 Eritreans were refugees who had fled Eritrea. Factors corresponding to emigration include the "lack of political, religious and social freedom", economic reasons and indefinite military service. Young people choosing to flee Eritrea often keep their plans secret from their families in order to decrease their families' stress and risk of being fined or imprisoned. Payment to people smugglers is typically made when a refugee arrives in Libya and provides the smugglers with a telephone number of a diaspora contact who is expected to pay. Several refugees given educational opportunities while residing in refugee camps in Ethiopia felt that they lacked long-term life opportunities beyond obtaining academic degrees, motivating them to attempt further emigration to Europe.

During the first four half decades of the twenty-first century, UN DESA Population Division, in its 2019 Revision of World Population Prospects, estimated that Eritrea had 227 thousand more immigrants than emigrants during 2000–2005 (more people arrived than left), and had net outflows afterwards, with 80 thousand net emigrants during 2005–2010, 246 thousand during 2010–2015 and 199 thousand during 2015–2020.

Ethno-linguistic groups

Eritrea's population comprises nine recognized ethnic groups, most of whom speak languages from the Ethiopian Semitic branch of the Afro-Asiatic family. The East African Semitic languages spoken in Eritrea are Tigre, Tigrinya, and the newly recognized Dahlik. Other Afro-Asiatic languages belonging to the Cushitic branch are also widely spoken in the country. The latter include Afar, Beja, Blin, and Saho.

In addition, languages belonging to the Nilo-Saharan language family (Kunama and Nara) are spoken as a mother tongue by the Kunama and Nara Nilotic ethnic minorities that live in the north and northwestern part of the country. The Rashaida speak Arabic, while there are also a number of Italians who speak their native Italian language.

Afro-Asiatic communities

Semitic speakers Tigrinya

The majority of the Tigrinya inhabit the highlands of Eritrea; however, migration to other parts of the country has occurred. Their language is called Tigrinya. They are the largest ethnic group in the country, constituting about 50% of the population. The predominantly Tigrinya populated urban centers in Eritrea are the capital Asmara, Mendefera, Dekemhare, Adi Keyh, Adi Quala and Senafe, while there is a significant population of Tigrinya in other cities including Keren, and Massawa. They are 92% Christians, (of which 90% are of the Eritrean Orthodox faith, 5% Roman Catholic and Eastern Catholic (whose mass is held in Ge'ez as opposed to Latin), and 5% belonging to various Protestant and other Christian denominations, the majority of which belong to the (Lutheran) Evangelical Church of Eritrea). Tigre

The Tigre reside in the western lowlands in Eritrea. Many also migrated to Sudan at the time of the Ethiopian-Eritrean conflict and lived there since. They are a nomadic and pastoralist people, related to the Tigrinya and to the Beja people. They are a predominantly Muslim nomadic people who inhabit the northern, western, and coastal lowlands of Eritrea, and constitute 30% of the country's population. Some also inhabit areas in eastern Sudan. 95% of the Tigre people adhere to the Islamic religion Sunni Islam, but there are a small number of Christians among them as well (often referred to as the Mensaï in Eritrea). Their language is called Tigre. Rashaida