Map of Sex Ratio by County

This is an interactive map of Male to Female Ratio by U.S. county. Pink shades represent higher number of women. Blue shades represent higher number of men. Hover over the map to see the county, state, male population, female population, ratio, and total population. Zoom in for more detail. Scroll down for more information.

Sex Ratio

The sex ratio of a population is defined as the ratio of the number of individuals of one sex to that of the other sex.

It would be expected that the ratio of males and females at birth is equal. Nevertheless, at birth there are 105 more males for every 100 females.

Sex Ratio has several implications and why it is important to study it.

The proportion of females indicates the reproductive potential of a population. Source: Science Direct.

Sex ratio affects patterns of violence, family formation dynamics, polygamy, monogamy and more. Nature.

At birth there are more males than females in the United States, but it inverts around age 30 due to higher male mortality rates.

Sex Ratio in the USA

In the U.S. 2020 Census Females comprise a slightly larger share (50.9%) of the total population.

Females have outnumbered males since the 1950s. Before that, men outnumbered women. Census Bureau.

Alaska is the State with the highest ratio of males to females, followed by North Dakota.

Mississippi is the state with the lowest ratio of females to males, followed by Alabama.

The data on this map is from the 2023 American Community Survey 5-year estimate.

If you want to read more about sex ratio in different populations Amazon has Too Many Women?: The Sex Ratio Question.

Counties with more Females than Males

Foard County, Texas: 68
Robertson County, Kentucky: 71
Borden County, Texas: 72
Jones County, South Dakota: 73
McMullen County, Texas: 75

Counties with more Males than Females

Forest County, Pennsylvania: 244
Crowley County, Colorado: 227
Aleutians West Census Area, Alaska:227
Kalawao County, Hawaii: 207
West Feliciana Parish, Louisiana: 212

Historically Alaska has had more men than women. It used to be because of the gold rush.

Now days it is probably because of industries like fishing and oil which tend to be male-dominated and are most prevalent. Source: ADN.

Other industries like mining, forestry may also explain higher male to female ratios.

When it comes to life expectancy women usually outlive men. This could be related to working environment in factories, alcohol consumption, or as mentioned before, violence.

It is also possible that migration patterns from other countries bring different ratios of females to males.

Meanwhile, migration within the United States results in retirees flocking to southern states. In such locations it is possible to see females outliving their husbands.