Top 10 countries by share of births outside marriage
Rankings use the latest available figures (years differ by country). The metric is the share of live births outside marriage (%, latest year). In many places this largely reflects cohabiting parents rather than lone mothers.
Big picture. Since the 1970s, the share of children born outside marriage has surged across most OECD countries—on average from about 7% in 1970 to over 40% by 2020, with several countries above 60%. Latin America has long combined high cohabitation with high non-marital birth shares. In contrast, parts of East Asia and some MENA countries still report very low levels due to legal, cultural and economic norms.
City vs. countryside. Urban housing costs and delayed marriage push births toward later ages—and more births occur to cohabiting partners before or instead of marriage. Rural areas can sustain both earlier marriage and stable cohabitation; the balance varies by country.
- Cohabitation vs. single parenthood: high non-marital birth shares often reflect two-parent cohabitation, not necessarily a rise in single-parent homes.
- Comparability: reference years differ; some series (Eurostat/OECD) exclude certain territories; small states can be volatile. Treat Top-10 lists as indicative.
OECD Family Database (indicator SF2.4, “Share of births outside marriage”); Eurostat fertility/marriage releases (2023–2025); Our World in Data’s OECD-based series (retrieved Oct 7, 2025). For historical and non-OECD context see UN/CEPAL/UNICEF regional work and syntheses.
Interpretation. Very low shares often reflect strong marriage norms and/or legal and administrative frameworks in which births to unmarried mothers are uncommon or under-registered; they do not necessarily imply low rates of cohabitation or non-marital unions.
Sources: OECD Family Database SF2.4 (Japan, Korea, Turkey, Israel); Eurostat 2023 overview; regional syntheses noting ≈1% in several large Asian/African countries.
