In Boston, Ally Darling is a thirty-something woman who is struggling to make better decisions with her life. Her boyfriend Rick breaks up with her when she asks him to attend her sister Daisy's upcoming wedding, and she then gets laid off from her job. While taking the subway home, Ally comes across a Marie Claire magazine article entitled "What's Your Number?", which says that women who have more than twenty lovers in their lifetime have difficulty finding a husband. After making a list of all the men she slept with, she realizes that her number is nineteen, making her decide not to have sex with anyone else until she finds "the one". This lasts all of a few hours when she wakes up after Daisy's bachelorette party and discovers that she's hooked up with her ex-boss Roger whilst intoxicated. Hoping to avoid an awkward confrontation, Ally lets her musician neighbor Colin Shea into her apartment so that Roger will leave. It turns out that Colin was only over to avoid a girl that he slept with, because he doesn't want to give the women he sees any expectations. Ally then runs into "Disgusting Donald", her once overweight ex-boyfriend who is now successful and good-looking, and his fiancée. She decides to track down all her exes hoping that one of them will have grown into the man she wants to marry, and therefore the number of men she has slept with will never have to increase. She gets help from Colin, who is skilled in 'digging up dirt', to find all her exes in exchange for letting him stay in her place after his one-night stands, telling Colin to pay particular attention to one ex Jake Adams, who Ally sees as 'the one that got away'. Things do not quite work out the way she expected and Ally remembers why it didn't work out with those men in the first place, ranging from one man having stayed in the same job since their break-up to another requiring her to pretend to be British. Depressed after an unsuccessful search, Ally has a night out with Colin that culminates in the two growing closer and almost having sex. She stops him, but without a boyfriend decides to take him as her date to Daisy's wedding. Daisy and Ally's friends worry she is falling for Colin and warn her off him, reminding her of his promiscuous nature. Soon Ally is furious when she finds out that Colin had found Jake Adams' contact details after all but withheld them in the belief that they were going to become an item, and the two have a falling-out. Ally successfully contacts Jake, and the two begin to date again. Ally attends her sister's wedding with him while Colin and his band perform at a different wedding. During a slow-dance with her dad at the reception, he makes her realize that her happiness lies in being herself and not making her mom, who wants her to marry Jake Adams for a better future, happy. In another slow dance with Jake, Ally confesses her 'number' to Jake, and Jake, thinking she is joking, expresses disgust at the thought. Ally quickly realizes that her true feelings lie with Colin, and she and Jake are incompatible, breaking it off with him, in the process casting aside her fears over her number. Ally then has to run to numerous weddings before she finally finds Colin and confesses her feelings. Waking up with Colin the next morning, Ally gets a call from an old fling telling her that they in fact did not sleep together. Ally rejoices in the fact that Colin is indeed the 20th and last man, with whom she will ever sleep.
What's Your Number? grossed $14 million in the U.S. and Canada and $16.4 million in other territories, for a total gross of $30.4 million against a budget of $20 million. It grossed $5.4 million in its opening weekend, finishing 8th at the box office.
Critical reception
What's Your Number? received negative reviews from critics. On Rotten Tomatoes the film has a rating of 24%, based on 113 reviews, with an average rating of 4.24/10. The website's critical consensus reads, "The comic timing of Anna Faris is sharp as always, but it's wasted away in this predictable, boilerplate comedy." Metacritic gives the film a score of 35 out of 100, based on 31 critics, indicating "generally unfavorable reviews".
