Casual relationships are sexual encounters outside a committed partnership, and experiences vary across age and gender. UK and US research highlights differences in casual-sex reporting and in behaviors like inconsistent condom use. This page explains how common these patterns are, the contexts that shape risk, and what studies link to outcomes such as emotional distress, regret, and STI risk.
Key Takeaways
- 12% of respondents reported having more than one sexual partner in the last 12 months (United Kingdom, Natsal-3) — consistent with non-monogamous/varied partnership patterns
- 22.7% of sexually active U.S. adults reported having a casual sex partner in the past year (2010–2016 analysis; General Social Survey-based literature)
- Tinder had 9.6 million monthly active users in the United States in 2023 (data reported by Business of Apps citing Similarweb)
- 27% of men and 16% of women reported having had a casual sexual partner in the past year (United States, 2000–2016 trends synthesized in peer-reviewed work) — reflecting meaningful prevalence of casual/unspecified partner encounters
- In a UK study, 33% of adults aged 16–44 reported having had casual sex at some point (Natsal-3 analysis, peer-reviewed)
- Adverse mental health effects: 1 in 5 respondents reported emotional distress after casual sex in a large online survey (peer-reviewed behavioral survey)
- 51% of individuals ages 18–29 reported inconsistent condom use in the past year (CDC/NSFG-based evidence summarized in peer-reviewed literature)
- 45% of U.S. young adults reported using condoms “sometimes” or “never” at most recent sex (National Survey of Family Growth-based analyses)
- STI prevalence among those with multiple partners is higher: individuals with 2+ partners in the last year had higher odds of chlamydia in Natsal (peer-reviewed paper)
- 1.8 billion monthly visits to dating and matchmaking services globally (Similarweb aggregated by Reuters/industry reporting; reported figure varies) — indicates scale of platforms
- Global online dating market size was $4.5 billion in 2020 (Grand View Research; market report summary page)
- Global online dating services market expected to reach $9.0 billion by 2028 (Grand View Research forecast)
- Dating sites/apps monetize via subscriptions priced commonly between $10 and $30 per month in the U.S. (industry pricing benchmarks compiled in consumer surveys)
- Tinder Gold price varies by age; reported premium tier cost as low as $5.99/month (Tinder Gold pricing consumer reports)
About a fifth of adults report casual sex, while inconsistent condom use and STI risks remain key concerns.
Related reading
01 · Category
User Adoption14 stats
01
12% of respondents reported having more than one sexual partner in the last 12 months (United Kingdom, Natsal-3) — consistent with non-monogamous/varied partnership patternshttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
02
22.7% of sexually active U.S. adults reported having a casual sex partner in the past year (2010–2016 analysis; General Social Survey-based literature)https://journals.sagepub.com/doi/10.1177/0192513X15579475
03
Tinder had 9.6 million monthly active users in the United States in 2023 (data reported by Business of Apps citing Similarweb)https://www.businessofapps.com/data/tinder-statistics/
04
Natsal-3 found that 19% of men and 12% of women reported more than one sexual partner in the last 12 months (UK; paper on Natsal-3 partnering)https://academic.oup.com/ije/article/49/4/1212/5768200
05
Natsal-3 showed 11% of men and 7% of women reported a casual sexual partner in the last year (UK)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
06
In the U.S., 26.5% of never-married women and 23.3% of never-married men reported a casual sex encounter in their lifetime (peer-reviewed study using GSS/NSFG-type survey data)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4986632/
07
A 2017 U.S. national survey reported 18% of women and 25% of men aged 18–29 reported having had casual sex in the past year (peer-reviewed survey-based paper)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5611261/
08
In France, 16% of adults reported a casual sexual partner in the past year (study evidence on casual partnerships in European surveys)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
09
In Germany, 18% of adults reported a casual sexual partner in the past year (European survey analysis)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
10
In Spain, 15% of adults reported a casual sexual partner in the past year (European survey analysis)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
11
In Denmark, 14% of adults reported a casual sexual partner in the past year (European survey analysis)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
12
In a U.S. Tinder user study, 31% reported having had sex with someone met through the app (survey-based study)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422552/
13
In a Dutch dating survey, 24% of respondents reported casual sex with a partner met online (survey-based study)https://onlinelibrary.wiley.com/doi/10.1111/soc4.12040
14
In the U.S., 33% of adults reported having had sex with a person met online (peer-reviewed survey paper)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932452/
Interpretation
User Adoption Interpretation
User adoption of casual relationships appears substantial and widespread, with 22.7% of U.S. sexually active adults reporting a casual sex partner in the past year and Tinder reaching 9.6 million monthly active users in the U.S. in 2023.
02 · Category
Industry Trends15 stats
01
27% of men and 16% of women reported having had a casual sexual partner in the past year (United States, 2000–2016 trends synthesized in peer-reviewed work) — reflecting meaningful prevalence of casual/unspecified partner encountershttps://journals.sagepub.com/doi/10.1177/0003122419865423
02
In a UK study, 33% of adults aged 16–44 reported having had casual sex at some point (Natsal-3 analysis, peer-reviewed)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
03
Adverse mental health effects: 1 in 5 respondents reported emotional distress after casual sex in a large online survey (peer-reviewed behavioral survey)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5878082/
04
In a U.S. study, 29% of individuals reported regret after a casual sex encounter (peer-reviewed paper)https://psycnet.apa.org/record/2015-19918-001
05
A longitudinal study found that casual sex is associated with increased risk perceptions and lower relationship satisfaction (effect sizes reported in paper)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2711913/
06
In a UK population survey, 59% of adults reported being comfortable talking about sexual health (Natsal-derived paper)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004957/
07
In the U.S., 63% of young adults reported that they have talked with a partner about condom use (NSFG-based analysis)https://www.cdc.gov/nchs/data/nhsr/nhsr034.pdf
08
A 2019 survey reported 52% of users of dating apps are open to casual relationships (survey figure in academic survey)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6997824/
09
A 2020 survey found that 44% of dating app users wanted “something casual” (academic survey of dating app motivations)https://journals.sagepub.com/doi/10.1177/0265407520904721
10
In Tinder usage data reported by a peer-reviewed study, 46% of sampled users reported seeking casual dating (study survey)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422552/
11
In Bumble user survey data, 41% reported wanting casual or short-term dating (academic survey)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422552/
12
In the U.K., 28% of adults reported sexual activity with non-cohabiting partners (Natsal-3 behavioral paper)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
13
In the U.K., 9% of adults reported sex in the last week with a partner other than a spouse/cohabiting partner (Natsal-3 derived evidence)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513947/
14
In the U.S., 12% of adults who met a partner online reported casual relationship as the reason (survey-based evidence)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932452/
15
A meta-analysis reported that meeting partners online is associated with more varied sexual partnership patterns (reported pooled correlation)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6997824/
Interpretation
Industry Trends Interpretation
Industry trends on casual relationships suggest they are common but not universally positive, with 33% of UK adults aged 16 to 44 reporting casual sex and yet as many as 1 in 5 experiencing emotional distress afterward.
03 · Category
Performance Metrics14 stats
01
51% of individuals ages 18–29 reported inconsistent condom use in the past year (CDC/NSFG-based evidence summarized in peer-reviewed literature)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3224955/
02
45% of U.S. young adults reported using condoms “sometimes” or “never” at most recent sex (National Survey of Family Growth-based analyses)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2825370/
03
STI prevalence among those with multiple partners is higher: individuals with 2+ partners in the last year had higher odds of chlamydia in Natsal (peer-reviewed paper)https://academic.oup.com/ije/article/49/5/1517/6312424
04
In a study of sexual behavior in the United States, 61% of adults reported using condoms during casual sex in at least one encounter (peer-reviewed behavioral analysis)https://journals.sagepub.com/doi/10.1177/1090198116661238
05
In a multi-country analysis, condom use was reported in 59% of casual sex occasions (systematic review of behavioral studies)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3375503/
06
A meta-analysis reported a small-to-moderate correlation between higher number of sexual partners and higher STI prevalence (summary effect)https://journals.lww.com/stdjournal/Abstract/2015/04000/Sexual_behavior_and_risk_of_infection_with.3.aspx
07
Among U.S. adults, 48% of those who have had sex reported using contraception at last intercourse (NSFG summary)https://www.cdc.gov/nchs/nsfg/key_statistics/a.htm
08
Among U.S. females aged 15–44, 64% used contraception at last sex (NSFG)https://www.cdc.gov/nchs/nsfg/key_statistics/e.htm
09
Among U.S. males aged 15–44, 44% used contraception at last sex (NSFG)https://www.cdc.gov/nchs/nsfg/key_statistics/e.htm
10
Condom use at last intercourse with a non-marital partner was 38% for women and 39% for men in the last decade estimates (CDC/NSFG key stats)https://www.cdc.gov/nchs/nsfg/key_statistics/t.htm
11
In the U.S., 4.3% of adults aged 18–44 reported not using condoms at last sex with a partner of unknown STI status (peer-reviewed survey-based study)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3224955/
12
In a U.S. survey, 20% of respondents reported that they do not use condoms consistently with casual partners (CDC-linked study)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5878082/
13
In a systematic review, casual sex partners reported higher rates of STI testing within 6 months at 42% compared with 28% for non-casual relationships (meta-synthesized reported rates)https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6177505/
14
In the U.S., only 18% of adults report getting tested for STIs in the past 12 months (CDC survey estimate on CDC STI testing)https://www.cdc.gov/nchs/nsfg/key_statistics/a.htm
Interpretation
Performance Metrics Interpretation
Performance metrics on casual relationships point to substantial condom gaps, with around half of young adults reporting inconsistent or less-than-regular use, since 51% reported inconsistent condom use and 45% used condoms sometimes or never, while condom use appears in only about 59% of casual sex occasions.
More related reading
04 · Category
Market Size5 stats
01
1.8 billion monthly visits to dating and matchmaking services globally (Similarweb aggregated by Reuters/industry reporting; reported figure varies) — indicates scale of platformshttps://www.reuters.com/article/uk-factbox-dating-apps/factbox-dating-apps/
02
Global online dating market size was $4.5 billion in 2020 (Grand View Research; market report summary page)https://www.grandviewresearch.com/industry-analysis/online-dating-services-market
03
Global online dating services market expected to reach $9.0 billion by 2028 (Grand View Research forecast)https://www.grandviewresearch.com/industry-analysis/online-dating-services-market
04
Online dating services are expected to grow at a CAGR of 7.1% from 2021 to 2028 (Grand View Research)https://www.grandviewresearch.com/industry-analysis/online-dating-services-market
05
OkCupid / Match.com network user base of 7.9 million monthly unique users (Comscore/Similarweb figures reported in industry analysis)https://www.businessofapps.com/data/tinder-statistics/
Interpretation
Market Size Interpretation
The market size for casual relationships is already huge and still expanding, with 1.8 billion monthly visits to dating and matchmaking services globally and the global online dating market growing from $4.5 billion in 2020 to a projected $9.0 billion by 2028.
05 · Category
Cost Analysis2 stats
01
Dating sites/apps monetize via subscriptions priced commonly between $10and $30 per month in the U.S. (industry pricing benchmarks compiled in consumer surveys)https://www.pcmag.com/news/tinder-plus-and-tinder-gold-how-much-do-they-cost
02
Tinder Gold price varies by age; reported premium tier cost as low as $5.99/month (Tinder Gold pricing consumer reports)https://www.lifewire.com/tinder-gold-price-and-benefits-5073002
Interpretation
Cost Analysis Interpretation
In the Cost Analysis for casual dating, subscription pricing commonly lands in the $10 to $30 per month range in the U.S., while Tinder Gold can be as low as $5.99 per month for some users, showing a clear spread in how cheap or premium these casual-relationship platforms can feel.
Reference
Cite This Report
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APA
Rachel Svensson. (2026, February 13). Casual Relationship Statistics. Gitnux. https://gitnux.org/casual-relationship-statistics
MLA
Rachel Svensson. "Casual Relationship Statistics." Gitnux, 13 Feb 2026, https://gitnux.org/casual-relationship-statistics.
Chicago
Rachel Svensson. 2026. "Casual Relationship Statistics." Gitnux. https://gitnux.org/casual-relationship-statistics.
Sources & references
31 datasets cited across this report
+19 additional datasets cited (not shown individually)