For a new study, researchers asked women to make love with the stopwatch on their side.
They had to start it when they felt excited, and press stop when they reached orgasm.
Such a study has never been conducted before, the researchers said.
The special study by the Indian Kadave Institute of Medical Sciences shows that the women studied took between 5 minutes and 42 seconds, and the full 21 minutes, to get an orgasm.
Thus the average woman takes 13 and a half minutes to orgasm.
In comparison, another study by Geneva University in 2009, found that the average man just needs about six minutes to orgasm which is less than half the time it takes women.
Due to this rather big difference, female partners left feeling frustrated is being backed by the special study by Kadave Institute.
According to their study out of the 645 women one in six said that they had never experienced an orgasm during sex.
They also asked the women to find out which position gave them the best orgasm.
About 90 % of the women reported longer-lasting orgasms when they were on top in bed.
The research therefore only focused on straight women who have sex with men.
Around 645 women from 21 different countries participated in the study.
The study was published in the journal “The Journal of Sexual Medicine.”