Sex Ratio by U.S. County
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The sex ratio refers to the ratio of males to females within the population. It is typically expressed as the number of males per 100 females.
In the United States, the sex ratio at birth is typically close to 105 males for every 100 females. This slight male predominance at birth is a natural phenomenon observed in many countries.
The sex ratio can vary significantly across different age groups. In the early stages of life, there are typically more male births than female births. However, as people age, this ratio tends to become more balanced, and in older age groups, there may be more females than males due to women’s longer life expectancy.
The sex ratio can also vary by region within the United States. In some areas, such as rural regions or areas with specific industries that attract a predominantly male workforce, the sex ratio may be skewed in favor of males. In urban areas, the ratio may be more balanced.
Moreover different racial and ethnic groups may have varying sex ratios. These variations can be influenced by factors such as cultural preferences, immigration patterns, and historical events. For example, certain immigrant groups may have a different sex ratio than the overall population.
The map of the United States below, created using U.S. Census Bureau data, shows sex ratio by county. The sex ratio is calculated as the number of males per 100 females. U.S. counties with more men than women are marked in blue.
Male to female sex ratio
The sex ratio is calculated as the number of males per 100 females.
The sex ratio in the United States has evolved over time, influenced by a variety of factors, including changes in birth rates, life expectancy, immigration patterns, and societal attitudes.
In the early colonial period, sex ratios in America were often imbalanced, with more men than women due to the predominantly male settlers, especially in regions like Jamestown, Virginia. Over time, as families and communities grew, the sex ratio began to balance.
During the 19th century, the U.S. experienced rapid population growth and westward expansion. The sex ratio remained relatively balanced overall, with minor variations in specific regions or due to factors like the California Gold Rush.
The sex ratio at birth in the early 20th century was typically close to 105 males for every 100 females, consistent with the global average. After a peak of 106.2 in 1910, the sex ratio declined to a low of 94.5 in 1980. This long decline resulted mainly from the relatively larger reduction in female mortality rates during the period. The sex ratio then increased between 1980 and 1990, as male death rates declined faster than female death rates and as more male immigrants than female immigrants entered the country.
In recent decades, the sex ratio at birth has typically hovered around 105 males per 100 females.
Below is the animated map of the sex ratio by U.S. county from 2000 to 2022.
U.S. Counties With the Most Men (2020)
- Crowley County (Colorado) – 270 men to 100 women
- Stewart (Georgia) – 223 men to 100 women
- Forest (Pennsylvania) – 216 men to 100 women
- Aleutians East (Alaska) – 207 men to 100 women
- Aleutians West (Alaska) – 197 men to 100 women
- Garza (Texas) – 193 men to 100 women
- West Feliciana (Louisiana) – 187 men to 100 women
- Wheeler (Georgia) – 184 men to 100 women
- Chattahoochee (Georgia) – 182 men to 100 women
- Union (Florida) – 181 men to 100 women
U.S. Counties With the Most Women (2020)
- Pulaski County (Georgia) – 75 men to 100 women
- Macon (Alabama) – 83 men to 100 women
- Summers (West Virginia) – 83 men to 100 women
- Livingston (Missouri) – 83 men to 100 women
- Niobrara (Wyoming) – 84 men to 100 women
- Franklin City (Virginia) – 84 men to 100 women
- Petersburg (Virginia) – 84 men to 100 women
- Sumter (Alabama) – 84 men to 100 women
- Williamsburg (Virginia) – 85 men to 100 women
- Fluvanna (Virginia) – 85 men to 100 women
To learn more about demographics of the United States see:
Fantastic map. Almost all of these counties with these extremes tend to be poorer, rural, and in “flyover” states.
Women really outnumber men in many counties that are predominantly Black.
Men really outnumber women were there is oil, mining and forests… North Dakota, Washington, Texas, Alaska
Shouldn’t we a little concerned that the gender birth ratio is vastly different in the last 20 years than the last 200? Male: female birth ratio historically has always been male leading..,likd in all of history. Over time, males die younger and it becomes even. Men have specific genetic issues that women are insulated from simply by having 2 X chromosomes. Sex -linked diseases are almost absent in women. So for no one to be asking “why is there a 10% shift in the birth gender” is as concerning as the fact there’s a 10% shift in this ratio… this doesn’t just happen naturally.