TOP 20 Countries by Cohabiting Unmarried Couples Share (2025)
Cohabiting couples — partners who share a home in an intimate relationship outside marriage or registered civil partnership — now account for a substantial and growing share of adult partnerships across advanced economies. This ranking uses the latest available harmonized data (primarily 2020–2023 national censuses and OECD Family Database updates) as a 2025 snapshot of the share of adults aged 20+ living in such unions.
The OECD average is roughly 11–12 percent of adults aged 20+ living in a cohabiting union. In the leading countries, that figure almost doubles: in Iceland, Sweden and France more than one in five adults shares a home with an unmarried partner. These gaps reflect decades of demographic change, shifting legal frameworks and evolving cultural norms around family formation.
Iceland, Sweden, France, Estonia and Norway now lead the "cohabitation frontier", each recording 17–22 percent of adults aged 20+ in non-marital unions. Denmark, New Zealand, the Netherlands, Finland and the United Kingdom round out the top 10, all well above the OECD average. In most of these countries cohabitation is no longer a transitional phase before marriage: it is an established long-term family form, frequently including children.
Figures are harmonized and rounded for cross-country comparability. They serve analytical purposes and should not be read as official national statistics. Methodological notes are provided in Part 3.
The ten countries with the highest cohabitation shares
Each profile below explains what drives the country's position and what it tells us about the broader shift in family formation in that society.
Iceland has the highest cohabitation rate in the OECD, a position consistent across every data cycle since the 2000s. Cohabitation in Iceland is culturally equivalent to marriage: around 70 percent of births occur outside formal marriage, yet two-parent family stability is relatively high. A gender-equal labor market, individual-based taxation and generous parental leave remove most of the economic incentives to formalize a union.
Sweden coined the concept of sambo — a legally recognised cohabiting partner with defined rights in housing, inheritance and social insurance. The result is a near-parity between married and cohabiting couples in day-to-day legal and social terms. Swedish policy is largely neutral to marital status, and a high share of children (around 56 percent) are born outside marriage, mostly to stable cohabiting couples.
France stands out among large Western European economies for its very high cohabitation share. The introduction of the PACS (civil solidarity pact) in 1999 created a popular intermediate form between cohabitation and marriage, but a large segment of couples cohabit without any formal registration. More than 60 percent of births in France now occur outside marriage, underscoring how central non-marital family forms have become.
Estonia's high cohabitation rate reflects a rapid post-Soviet transition in family norms. Marriage rates fell sharply in the 1990s and never fully recovered. A large share of Estonian children — over 50 percent — are born outside formal marriage. The legal framework, while less comprehensive than Sweden's, increasingly recognises cohabiting partner rights.
Norway closely resembles Sweden in family-policy design: benefits, parental leave and housing support are broadly neutral to marital status. Roughly 57 percent of births occur outside marriage. Norwegian cohabiting couples are often long-term partnerships with children, not just early-relationship arrangements waiting for a wedding.
Denmark ranks among the top cohabitation countries with a cultural tradition of tolerating and accommodating diverse partnership forms. Danish family law has long extended certain rights to cohabiting partners. Around 55 percent of children are born outside marriage. The welfare state's support structure for parents applies regardless of marital status.
New Zealand's Property (Relationships) Act 1976 (amended in 2002) gives cohabiting couples of three or more years near-equal property rights to married couples. This strong legal recognition has accompanied a sustained rise in cohabitation. Roughly half of all births now occur outside marriage.
The Netherlands has a long tradition of pragmatic social liberalism. Registered partnership (introduced in 1998) and informal cohabitation both serve as alternatives to marriage. The share of non-marital births (~44 percent) is above the OECD average. Tax and benefit rules have become increasingly neutral to relationship status.
Finland's Act on Cohabiting Couples (2011) extended limited rights to unregistered partners in housing and estate matters. Together with a comprehensive universal welfare system, this has encouraged stable cohabiting arrangements. Close to 46 percent of Finnish births occur outside marriage.
The UK has seen one of the fastest increases in cohabitation among large OECD economies over the past two decades, yet its legal framework still provides much weaker protection for cohabiting partners than marriage — a gap that family-law reformers have long highlighted. Around 48 percent of births now occur outside marriage, reflecting how common cohabiting parenthood has become.
Table 1. Adults living in a cohabiting union — Top 10 (adults 20+, %)
| Rank | Country | Cohabiting adults 20+ (%) | Births outside marriage (%) |
|---|---|---|---|
| 1 | Iceland | 21.8 | 70.9 |
| 2 | Sweden | 20.4 | 55.7 |
| 3 | France | 19.1 | 62.2 |
| 4 | Estonia | 18.3 | 54.6 |
| 5 | Norway | 17.5 | 57.1 |
| 6 | Denmark | 16.2 | 55.3 |
| 7 | New Zealand | 16.0 | 50.2 |
| 8 | Netherlands | 15.6 | 44.1 |
| 9 | Finland | 15.1 | 46.2 |
| 10 | United Kingdom | 13.8 | 48.3 |
Cohabitation shares: OECD Family Database SF3.3, harmonized using 2020–2023 census rounds and latest available survey data. Births outside marriage: OECD SF2.4, mostly 2022–2024.
Chart 1. Adults in cohabiting unions — Top 10 countries (%)
Horizontal bars show the estimated share of adults aged 20+ living with an unmarried partner (2020–2023 census data). OECD average reference ≈ 11.5%.
Full country table: cohabitation share across OECD economies (2025 snapshot)
The table below covers all OECD and selected non-OECD economies for which comparable cohabitation data exist. The data are drawn from the 2020–2023 national census rounds and OECD Family Database SF3.3 updates. Use the search, filter and sort controls to navigate the full dataset. The Units / Share toggle switches the value column between the direct percentage and each country's share of the sum of all listed values (analytical, not a global-population weight).
Sum of listed values (analytical total): — percentage points across all listed economies.
| Rank | Country | Cohabiting adults 20+ (%) | Births outside marriage (%) | Region |
|---|---|---|---|---|
| 1 | Iceland | 21.8 | 70.9 | N. Europe |
| 2 | Sweden | 20.4 | 55.7 | N. Europe |
| 3 | France | 19.1 | 62.2 | W. Europe |
| 4 | Estonia | 18.3 | 54.6 | E. Europe |
| 5 | Norway | 17.5 | 57.1 | N. Europe |
| 6 | Denmark | 16.2 | 55.3 | N. Europe |
| 7 | New Zealand | 16.0 | 50.2 | Asia-Pacific |
| 8 | Netherlands | 15.6 | 44.1 | W. Europe |
| 9 | Finland | 15.1 | 46.2 | N. Europe |
| 10 | United Kingdom | 13.8 | 48.3 | W. Europe |
| 11 | Belgium | 13.5 | 52.4 | W. Europe |
| 12 | Canada | 13.1 | 30.6 | Americas |
| 13 | Portugal | 12.7 | 49.3 | W. Europe |
| 14 | Australia | 12.4 | 31.7 | Asia-Pacific |
| 15 | Spain | 12.2 | 47.6 | W. Europe |
| 16 | Austria | 11.9 | 43.1 | W. Europe |
| 17 | Switzerland | 11.6 | 35.6 | W. Europe |
| 18 | United States | 11.3 | 35.5 | Americas |
| 19 | Latvia | 10.9 | 48.8 | E. Europe |
| 20 | Germany | 10.7 | 44.8 | W. Europe |
| 21 | Slovenia | 10.4 | 51.2 | E. Europe |
| 22 | Lithuania | 10.1 | 47.0 | E. Europe |
| 23 | Ireland | 9.8 | 26.6 | W. Europe |
| 24 | Czech Republic | 9.4 | 49.3 | E. Europe |
| 25 | Luxembourg | 8.9 | 41.8 | W. Europe |
| 26 | Bulgaria | 8.6 | 57.4 | E. Europe |
| 27 | Chile | 8.2 | 29.1 | Americas |
| 28 | Slovakia | 7.9 | 48.0 | E. Europe |
| 29 | Italy | 7.6 | 17.3 | W. Europe |
| 30 | Greece | 6.8 | 23.0 | W. Europe |
Source: OECD Family Database SF3.3 (2020–2023 rounds); Eurostat census 2021; OECD SF2.4 for births outside marriage. Last updated: Q1 2025. Values rounded to one decimal place.
Chart 2. Cohabitation rate vs. births outside marriage — selected OECD economies
The scatter plot links each country's cohabitation share (x-axis) with the share of births occurring outside marriage (y-axis). The upward slope confirms the expected positive association: societies where cohabitation is widespread tend also to have a high proportion of non-marital births — because a large share of those births occur within stable cohabiting couple households, not as single-parent situations.
Each point represents one economy. X-axis: adults 20+ in cohabiting unions (%). Y-axis: births outside formal marriage (%). Data: OECD SF3.3 & SF2.4, latest available 2022–2024.
What the 2025 cohabitation data tell us about family change
The rise of cohabitation is one of the defining demographic trends of the past half-century in advanced economies. In the early 1970s, living together outside marriage was a marginal phenomenon in virtually every OECD country. By the mid-2020s, it has become a mainstream family form in the Nordic region, France, and a growing number of Central and Eastern European and English-speaking countries. Four themes explain the geography and depth of this transformation.
1. Cohabitation is no longer a trial marriage — it is a family form in its own right
In early sociological research, cohabitation was theorized primarily as a "prelude" to marriage or as a "trial" period before formal commitment. That framing fits parts of the English-speaking world and Southern Europe, where a large share of cohabiting relationships are young-couple arrangements that either progress to marriage or dissolve within a few years. But in the Nordic countries, France, and increasingly Estonia and Belgium, cohabitation functions as a stable, long-term partnership form that encompasses the full lifecycle, including parenthood and childrearing. The share of births to cohabiting (but unmarried) couples in Iceland, Norway and France — each exceeding 55 percent — is direct evidence of this transformation.
2. Legal frameworks shape — but do not fully explain — the pattern
Countries with the most comprehensive legal protection for cohabiting partners (Sweden's sambo law, New Zealand's Property Relationships Act, France's PACS regime) tend to show higher cohabitation rates, consistent with the idea that legal recognition lowers the barriers to choosing cohabitation over marriage. Yet Iceland leads the table despite having a thinner statutory framework for cohabiting partners than Sweden or France, suggesting that cultural norms and the gender-equality of welfare-state design can matter at least as much as property and inheritance law. The United Kingdom sits at the bottom of the top 10 despite very high public acceptance of cohabitation, partly because its legal framework still provides weak protection for cohabiting couples upon relationship breakdown — a deterrent that researchers argue depresses the measured share.
3. The "cohabitation effect" on births outside marriage is real but heterogeneous
The scatter chart in Part 2 confirms a strong positive association between cohabitation prevalence and the share of births outside marriage. But the slope is not uniform. Canada stands notably below the regression line: its cohabitation share is moderate, yet its non-marital birth share is well below what the Scandinavian pattern would predict. This partly reflects Canada's internal diversity — Quebec closely resembles France in both cohabitation and non-marital birth patterns, while the rest of Canada is closer to the US or Australian model. Bulgaria presents the mirror image: a moderate cohabitation share but very high non-marital births (above 57 percent), driven in part by high rates of childbearing outside any formal union among some marginalised communities.
4. The Eastern European story is one of rapid, culturally distinct convergence
Estonia and Latvia (and to a lesser extent Lithuania, Slovenia and the Czech Republic) have moved rapidly up the cohabitation ranking since the early 1990s. This was not a smooth convergence toward a Western model: it was partially driven by the collapse of formal marriage as an institution during the economic turbulence of the post-Soviet transition, and by the spread of what some demographers call "fragile cohabitation" — shorter, less institutionally embedded unions compared to the more stable cohabiting arrangements in Scandinavia. Policy infrastructure for cohabiting families in Eastern Europe remains thinner than in the Nordic region, which creates income and social-security vulnerabilities for children raised in these unions.
5. The United States: high acceptance, but only moderate measured prevalence
The United States sits at rank 18 with an estimated cohabitation share of around 11.3 percent — squarely at the OECD average. Survey data consistently show very high public acceptance of cohabitation as a valid life choice, and the number of cohabiting couples has roughly tripled since 1990. Yet the measured share of adults in cohabiting unions remains moderate by OECD standards. This reflects three factors: the very large share of the adult population that is already married (diluting the cohabiting percentage), the significant racial and income heterogeneity in cohabitation patterns (with cohabitation more prevalent among lower-income adults but with higher fragility), and the very limited federal legal recognition of cohabiting relationships compared to the Nordic model.
Bottom line for the 2025 snapshot: cohabitation is now a majority-accepted and institutionally embedded family form across Northern and Western Europe, with a combined cohabitation share (adults 20+) of 15–22 percent in the leading economies. The broad direction is clear: younger cohorts in virtually every OECD country are more likely to start partnerships in informal unions than their parents' generation — but the destination remains heterogeneous, shaped by law, welfare design and cultural inertia.
Methodology: how this ranking is constructed
Indicator definition
The headline indicator is the share of adults aged 20 and over who are living in a cohabiting couple household — that is, who share a dwelling with an intimate partner to whom they are not married and not in a registered civil partnership. The denominator is all adults aged 20+ residing in the country. Cross-border commuters and institutionalised populations are generally excluded.
Primary data sources
The core input is the OECD Family Database, indicator SF3.3 ("Cohabitation and forms of partnership"), which compiles harmonized estimates from national censuses and large-scale household surveys. The 2025 snapshot draws on:
- National census rounds of 2020–2023 (Eurostat Census Hub for EU/EEA members; Statistics New Zealand 2023; Statistics Canada 2021; ABS Australia 2021).
- Eurostat Labour Force Survey (LFS) household composition module, used for inter-census years where census data are not yet available.
- OECD Family Database SF2.4 for births outside marriage, drawing on civil-registration data for 2022–2024.
Year of data and proxy rationale
Census data are collected every five to ten years. No single source provides fully synchronized 2024 or 2025 figures for all countries. The estimates in this ranking are therefore the most recent available data point per country (mostly 2021–2023), adjusted marginally upward for countries where the long-run trend has been consistently positive (Nordic countries, Western Europe) and held flat for countries showing saturation (e.g. Latvia). These adjusted values are used as a structural snapshot for around 2025, not as precise point estimates.
Harmonisation and comparability limitations
- Age group: OECD SF3.3 reports adults 20+; some national sources use 18+ or 15+. Values have been rescaled to an approximate 20+ basis where necessary, which may introduce small upward or downward adjustments.
- Definition of "cohabiting union": some surveys ask about any co-resident partner; others specifically ask about non-married partners. The difference can matter in countries with high same-sex registered-partnership rates.
- Population coverage: countries with large immigrant populations may under- or over-count cohabiting unions depending on the survey frame.
- Rounding: all figures are rounded to one decimal place. Differences of 0.1–0.3 percentage points should not be interpreted as meaningful ranking changes.
What this indicator does not capture
GDP-style aggregates, population-weighted averages, or economic output are not involved in this ranking. The indicator measures a partnership form, not wellbeing, income or family stability. It should be triangulated with data on union dissolution rates, child outcomes, housing tenure, and legal protections to form a complete picture of family life in each country.
How to interpret this ranking
Whether you are a researcher, policymaker, journalist, or someone thinking about how family norms differ across borders, here is what the data most usefully tell you — and where they fall short.
- High rank ≠ weaker families. Countries with the highest cohabitation shares — Iceland, Sweden, Norway — also score among the highest on child wellbeing, gender equality and social trust. Cohabitation in these societies is not a symptom of family breakdown but of a reconstituted family model that functions effectively within a supportive legal and welfare environment.
- Low rank ≠ traditional families. Countries with low formal cohabitation rates sometimes have high rates of informal (unregistered) partnerships or multi-generational household arrangements that simply are not captured by this indicator.
- The legal context defines the risk. A cohabiting couple in Sweden faces almost no legal or financial disadvantage compared to a married couple. A cohabiting couple in the United Kingdom — or even more so in Southern or Eastern Europe — may face significant gaps in inheritance rights, housing protection and social-benefit access. The same headline number carries very different social implications depending on the legal framework.
- Cohort trends matter more than cross-section levels. In many OECD countries, younger cohorts (born after 1985) begin their adult partnership trajectories almost exclusively through cohabitation. The current adult-population share of cohabiting couples understates how central cohabitation has become as a starting point for families in these countries.
- For policymakers: if your country is seeing rapid cohabitation growth without concurrent legal reforms, a growing share of adults and children may be exposed to significant protection gaps. The Nordic and French experience suggests proactive legal design — not restricting cohabitation, but ensuring it does not carry undue risks — is the effective policy response.
FAQ
What exactly counts as "cohabiting" in this ranking?
Why is Iceland ranked first when Sweden is usually seen as the most progressive on family issues?
Does a high cohabitation share mean higher divorce or separation rates?
Why is Japan not in the ranking?
Is cohabitation growing in all the countries listed?
How often is this ranking updated?
Where does the OECD average figure of ~11.5% come from?
Primary data sources and further reading
The figures and charts in this article draw on the following primary sources. All are openly accessible through the links provided. Figures are harmonized and rounded; for formal statistical work always refer to the original databases.
-
OECD Family Database — SF3.3 "Cohabitation and forms of partnership"
Core source for the share of adults in cohabiting unions. Covers OECD member countries using
harmonized census and survey data. Updated approximately every 1–2 years.
https://www.oecd.org/en/data/datasets/oecd-family-database.html -
OECD Family Database — SF2.4 "Share of births outside marriage"
Annual civil-registration data on the share of live births occurring outside formal marriage.
Covers OECD members plus selected partner countries. Latest data: 2022–2024.
https://www.oecd.org/en/data/datasets/oecd-family-database.html -
Eurostat — 2021 Census Hub (Population and Housing Census)
Provides harmonized household composition and partnership-status data for EU and EEA member states
from the 2020–2022 census round. Used for European country estimates.
https://ec.europa.eu/eurostat/web/population-and-housing-census/census-data -
Eurostat — Labour Force Survey (LFS), household composition module
Annual EU-wide survey providing inter-census estimates of household and partnership structure.
https://ec.europa.eu/eurostat/web/microdata/european-union-labour-force-survey -
Statistics Canada — Census of Population 2021
Provides detailed household and partnership composition data for Canada, including Quebec-vs-rest breakdown.
https://www12.statcan.gc.ca/census-recensement/2021/dp-pd/index-eng.cfm -
Statistics New Zealand — Census of Population and Dwellings 2023
New Zealand's latest national census; provides partnership and household status data.
https://www.stats.govt.nz/topics/census -
Australian Bureau of Statistics (ABS) — Census of Population and Housing 2021
Used for Australian household composition and partnership data.
https://www.abs.gov.au/census - Soons & Kalmijn (2009). "Is Marriage More Than Cohabitation? Well-Being Differences in 30 European Countries." — Journal of Marriage and Family Foundational comparative study on the wellbeing implications of cohabitation vs. marriage across European societies.
- Cherlin, A. (2020). "Degrees of Change: An Assessment of the Deinstitutionalization of Marriage Thesis." — Journal of Marriage and Family Review article assessing the strength and limits of the deinstitutionalisation thesis for understanding cohabitation trends in the US and comparable societies.
All numerical values are indicative and rounded for clarity. This page uses a 2025 snapshot based on 2020–2023 census rounds and OECD database releases. For formal statistical or policy work, consult the original databases directly.
