It’s the million pound question: exactly how often, on average, should a couple be having sex to ensure a long-lasting, meaningful relationship.
The figure may seem deeply personal—and dependent on a slew of different factors, including age, whether or not a pair have children and whether they live together.
But a world-leading expert says she knows exactly much sex couples should have to keep the relationship alight—and the answer may just surprise you.
Professor of human sexuality Dr Nicole McNichols teaches one of the most popular classes at the University of Washington.
The course, titled The Diversity of Human Sexuality, is packed with more than 4,000 students each year, and almost always has a waitlist.
Students are asked to interrogate what makes for a satisfying sex life—and told to analyse their own as a jumping off point.
Many people, Dr McNichols explains, often assume that a good time in the bedroom is dependent on having a good relationship with your partner more generally.
But actually, she points out, research has found the opposite to be true: the better the sex a couple has, the more likely they are to think of their relationship as satisfying, and the longer they tend to stay together.
Professor of human sexuality Dr Nicole McNichols says she knows exactly how much sex couples should be having to ensure a successful long-term relationship
Examining longitudinal data mapping the relationship trajectories of thousands of couples over time, Dr McNichols found that sexual satisfaction preceded relationship satisfaction in the majority of cases.
‘If you look at couples over time who are asked to keep daily diaries of how satisfied they feel in their relationships and what their mental well-being is—including how happy and satisfied with life they feel overall, and how satisfying their sex life is— what you see is that when an uptick in sexual satisfaction occurs, the joy and satisfaction in the relationship follows,’ she explained on the New York Times’ Modern Love podcast.
‘So it’s a pathway in that people don’t really appreciate enough, I don’t think.’
Luckily for busy couples, Dr McNichols says, that doesn’t mean you need to be having sex all the time.
In fact, the data shows there is a sweet spot for how often a couple needs to get intimate. And it’s less than you might expect: just once a week.
If couples want to have sex more than that, that’s fantastic for them, says Dr McNichols—but it won’t necessarily make their relationship stronger.
‘When we look at the benefit of sex to relationship well-being, it doesn’t increase after about once a week,’ she explained.
‘That’s not an astronomical amount of time.’
And it’s not just frequency that Dr McNichols says is important to consider.
Couples with the strongest relationships, research shows, also introduce something new to their sex lives roughly once a month.
‘It does not need to mean that you’re going to a sex shop and buying a bunch of leather and buying a nurse outfit,’ said Dr McNichols.
‘That’s fantastic if you want to try that. But it can be as subtle as instead of missionary, lifted missionary.
‘You can either put a pillow underneath the woman’s hips or her legs around her partner’s neck, which is going to elevate the pelvis into an angle that is going to be more pleasurable and more likely to lead to orgasm for her, increasing surface area of the places that feel the best for her.
‘It could be having sex in a different room, having sex while you’re on vacation, having sex at a different time of day than you normally do, having sex, that is, with all the lights on, having sex with the lights off.
‘It really is about owning your own particular brand of what makes you come to a sexual situation feeling empowered to show up, assert your own needs, communicate, and have a mutually pleasurable experience.
‘And it’s really about taking ownership, taking that responsibility into your own hands and knowing that you have the power to do it.’
Recent research seems to confirm Dr McNichols’s theory.
Scientists from the University of Manchester found that 85 per cent of women who had sex once a week described themselves as ‘sexually satisfied’, according to a 2025 study of nearly 500 heterosexual women.
In contrast, only 66 per cent of wives and girlfriends who had sex once a month reported the same level of relationship bliss.
And the figure fell to 17 per cent among those women who had intercourse less than this.
The data showed that satisfaction was also higher for women who reported more regular orgasms and rated sex as an important part of their life.
In the UK, many couples have more work to do, it seems.
YouGov figures reveal that six in 10 Britons have sex less often than once a week.
One in 10 claim to have sex weekly, and 15 per cent claim to be sexually intimate more often.
Regular sex doesn’t just boost your mood, multiple studies have concluded that it is great for our overall health, and can even potentially help us live longer.
