The survey by Wonderbra for the National Cleavage Day found one in seven women wear plunging necklines at work to impress the boss or push for a pay rise. One in 10 tried to upstage the bride at a wedding with eye-popping cleavage while eight percent of them treated a traffic warden to an eyeful to dodge a ticket, the Sun reported.
The study found four in five women admitting to regularly eyeing other girls' assets. Almost a third of girls, however, made sure their cleavage was always uncovered on the first date.
Many women admit to eyeing up their female pals to compare chests and even check out celebrity breasts to see how they measure up. The phenomenon is being dubbed "breast friends" and is not unique to Britain, the Sun reported.
Women around the world are snatching sly looks but it is the Brits who are out in front when it comes to using the breasts to get ahead, it added.
The survey found two-thirds regularly flash the flesh to feel feminine and sexy. But just three percent admitted they would bare more breast at a job interview while 90 percent kept covered up at school reunions.
Wonderbra spokesman Martina Alexander said: "Showing your cleavage is the embodiment of empowerment... What better excuse for women to celebrate their curves than today, National Cleavage Day?"
The bra brand's poll of 1,000 women found girls' favourite "cleavage moment" of all time was Marilyn Monroe wearing her daring low-cut white dress in hit 1955 film "The Seven Year Itch".