The U.S. population was more than 311 million, with females comprising 50.8 percent of the total population. Females younger than 18 years accounted for nearly one-quarter of the 158 million U.S. females, while women aged 18–44 years accounted for 35.6 percent, those aged 45–64 years accounted for 26.8 percent, and women aged 65 years and older accounted for 14.8 percent.

The distribution of the population by sex was fairly even across younger age groups; however because women have longer life expectancies, they represented a greater proportion of those aged 65 years and older in 2011. Women accounted for 56.7 percent of all individuals aged 65 years and older, 60.5 percent of individuals aged 75 years and older, and over two-thirds of individuals aged 85 years and older (67.0 percent; data not shown in graph images or in data tables on this site).

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