A new study explains why it’s impossible for some women to orgasm during sex

…and it’s not to do with penis size.

It’s been long debated as to why some women can orgasm through penetrative sex and others can’t, and now a study by the University of Indiana has found that orgasms have less to do with your partner’s penis size, and more to do with the size and shape of your vagina.

Here’s the maths: Researchers found that women with a clitoris positioned 2.5sm or less to their urinary tract will be able to orgasm through penetrative sex, as it allows for sufficient friction around her clitoris, which helps enable orgasm.

However if the clitoris 3cm or more away from the urinary tract, achieving an orgasm will be pretty much impossible, meaning it's probably time to seek out one of the best sex toys to help you along the way.

Elizabeth Lloyd from The Kinsey Institute told the Medical Xpress: 'The magic number is 2.5cm. It's so strong a correlation that if you give us a woman who has a distance of 3 centimetres, we can very reliably predict she won't orgasm with intercourse.’

However, it’s not bad news if you don’t make the 2.5cm measurement, as this can help explain why you’re struggling to reach the big O during sex, and start concentrating on other ways to achieve orgasm.

'Women can do this measurement themselves or with their partner, to help explain their own sexual experience,’ explained Lloyd.

She added: ‘Of those that claim they can have purely vaginal orgasms, 90 percent of them say they have to be on top. Guess what? When you're on top, sitting on the partner's erection and grinding on his abdomen, it's really not just a vaginal orgasm. You're rubbing your clitoris on his abdomen or pelvis.’

So while it’s great news that there has been more research into women’s sexual enjoyment, we’re also left wondering why it’s taken until 2016 to be this thoroughly looked into…