Jessica Alba Costume Institute Gala Benefit metallic one-shoulder gown

Jessica Alba flaunts her perfect form. Photo: Kevin Mazur, WireImage

Bust out the measuring tape!

A New Zealand anthropologist has determined the perfect female waist-to-hip ratio for getting instant sexual attraction from men, the Daily Mail reports.

Researcher Barnaby Dixson has concluded that having a .7 waist-to-hip ratio, or a waist measurement that is 70 percent of the hip circumference, will help ladies lure the fellas, according to the paper.

Exhibits A, B, and C: Kate Moss, Jessica Alba, Marilyn Monroe, and model Alessandra Ambrosio, who all reportedly boast the desirable body.

"It is likely that perfect 0.7 ratio sends a biological signal to men that that woman is most fertile and most likely to produce a healthy offspring, no matter what size that woman is," Dixson explained on Australian TV, echoing a similar report that found that men are hardwired to find curvy female figures attractive.

"It is all about the distribution of fat, which is directly linked to fertility."

Greaaaat. Guess it's back to the stomach crunches for us.

Dixson also found that women are, on the whole, more attracted to men with a long, lean, and "slightly more effeminate" figure because we assume that they are more caring and gentle, the paper reports. (Oh, and guys? Wear something red.)

Additionally, both sexes reportedly tend to be attracted to others with the same level of attractiveness.

"Women and men with those traits we consider biologically perfect will consistently attract the most high-quality partner," Dixson said.

"Humans simply do not mate randomly; it is very time consuming... to pick a life partner."

No s--t, Sherlock! But we suppose we can at least stop wasting our time trying to score David Beckham's phone number.

Meanwhile, a recent study found British women are attracted to hairy men.