A recent study might have the answer.
Research conducted by Finnish scientists suggests women need 7.6 hours a night while men need 7.8 hours.
As the Independent reports, the study compared data from Finland's Social Insurance Institution sickness absence data to the sleeping patterns of 3,760 people. After analysing daytime sleepiness, sleep disturbances and the use of sleeping pills, the results found those who got over 7 hours a night were less likely to take sick days from work.
"Among women, after adjusting for age, insomnia-related symptoms, early morning awakenings, being more tired than others, and use of sleeping pills were associated with sickness absence," the research states.
It concluded, "Although persistence of other health problems could affect the estimates, direct costs due to sickness absence could decrease by up to 28Slideshow-2814%