Are you happy with the frequency of sex in your relationship?

Many men and women are not, according to the findings of a large Australian study that tracked sexual satisfaction and frequency of sex among heterosexual men and women in long-term relationships.

The researchers surveyed 3,240 men and 3,304 women who were married, living with a partner or in a relationship, asking them about their satisfaction with their sex lives. A majority of men (54 percent) and nearly as many women (42 percent) said they were unhappy with the frequency of sex, according to the report, published in the March issue of The Journal of Sex & Marital Therapy.

For most men, the complaint was that they weren’t having sex often enough. Among women who were unhappy about the frequency of their sex lives, two-thirds said they weren’t having enough sex, but a third complained they were having more sex than they wanted.

Among the respondents, 73 percent were married, and 60 percent had been with their spouse or partner for 10 years or more. Men ages 35 to 44 who had been with a woman for six years or longer were the most likely to be unhappy with how often they had sex.

Men and women who were unhappy with the frequency of sex in their relationship were also most likely to report lower levels of overall relationship satisfaction.

“The majority of people in the study would prefer more sex than they’ve been having,’’ said Anthony Smith, professor of public health and deputy director of the Australian Research Center in Sex, Health and Society at La Trobe University in Melbourne. “What we’re seeing is that there is quite a gap between a person’s ideal frequency of sex and what they manage to achieve in their relationships.’’

The fact that both men and women are unhappy with the frequency of sex in their relationships suggests it’s not just an issue of differing sex drives, but of other tasks and obligations competing for a couple’s time.

“The real issue here, I think, is that couples are not finding enough time for sex,’’ said Dr. Smith. “I don’t think you can keep forcing more and more activities in people’s lives and still expect them to take the time it takes to have sex, let alone good-quality sex.”

Anthony Lyons, a study co-author and research fellow at La Trobe, said the main lesson from the study is that couples need to learn how to communicate about their sexual needs or their reasons for not wanting sex.

“Couples need to talk about the frequency of sex,” Dr. Anthony said in an e-mail. “Talking openly about sex and finding a middle ground with regard to frequency appears to be very important for overall sexual and relationship satisfaction.”

One solution may be to schedule time for sex, just as couples set aside time for meals, work and family activities, said Dr. Smith.

“Couples need to ask each other, ‘How much time do we want to spend having sex or being intimate, and what needs to go out of our schedule to make that time available?’ ” said Dr. Smith. “If people value sex as an important part of their relationship, and almost everybody does, then they need to put sex higher up the priority list.’’