O'Fallon, MO population by gender
The table below shows O'Fallon's population by gender
Gender | Population | % of Total Population |
---|---|---|
Female | 46,063 | 50.73% |
Male | 44,739 | 49.27% |
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O'Fallon, MO population by gender, in percentage
The female percentage in the USA is 50.50% while the male percentage is 49.50%, compared to 50.73% females and 49.27% males in O'Fallon, MO.
The above comparison shows there are more females than males in the O'Fallon city as compared to the nation.

O'Fallon, MO gender ratio
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021
In O'Fallon, MO, there are less men than women. The O'Fallon, MO gender ratio is 97.1:100 i.e. 97.1 men to 100 women (0.971).
This ratio is lower than the national average of 98:100 i.e 98 men to 100 women (0.980).
O'Fallon, MO gender ratio by age
In O'Fallon, MO, the sex ratio for children under 18 years is 104.5 boys per 100 girls (104.5:100).Having said that, for seniors aged 80 and older, there are 52.2 males per 100 females (52.2:100).
On the national level, the sex ratio (male per 100 females) for under 18 age group is 104.8:100, and 64.5:100 for the senior population 80 years and older.
The table below lists the male and female population in each age group along with the gender ratio for O'Fallon, MO.
Age Group | Population (Male) | Population (Female) | Gender Ratio |
---|---|---|---|
Under 5 years | 3,179 | 3,018 | 1.05 |
5 to 9 years | 3,175 | 3,178 | 1.00 |
10 to 14 years | 3,705 | 3,138 | 1.18 |
15 to 19 years | 3,255 | 3,107 | 1.05 |
20 to 24 years | 2,350 | 2,091 | 1.12 |
25 to 29 years | 3,045 | 2,944 | 1.03 |
30 to 34 years | 2,802 | 3,494 | 0.80 |
35 to 39 years | 3,433 | 2,933 | 1.17 |
40 to 44 years | 2,948 | 3,296 | 0.89 |
45 to 49 years | 3,285 | 3,096 | 1.06 |
50 to 54 years | 3,342 | 3,405 | 0.98 |
55 to 59 years | 2,787 | 3,392 | 0.82 |
60 to 64 years | 2,861 | 2,640 | 1.08 |
65 to 69 years | 1,557 | 2,277 | 0.68 |
70 to 74 years | 1,312 | 1,299 | 1.01 |
75 to 79 years | 866 | 1,151 | 0.75 |
80 to 84 years | 575 | 734 | 0.78 |
85 years and over | 262 | 870 | 0.30 |
Interesting observation from the above table:
- The sex ratio at birth is 1.053 i.e. 105.3 boys per 100 girls.
- For the 60-64 years, the sex ratio is 1.084 i.e. 8.4 more men per 100 women.
- While for senior most population of 85+ age group, the sex ratio is 0.301 i.e. 30.1 senior men per 100 senior women.
O'Fallon, MO population by gender & age
For male population, the largest age group is 10-14 years with a population of 3,705. Whereas, for the female population, the largest age group is 30-34 years with a population of 3,494.
As you can note from the above numbers, the largest age group for men and women are different.

Under the age of 5, there are 3,179 boys and 3,018 girls in O'Fallon, MO. Thus there are 161 more boys than girls under the age of 5.
Between the age group of 60-64 years, there are 2,861 males and 2,640 females in O'Fallon, MO. Thus there are 221 more males than females between the age of 60 and 64 years.
For the senior most age group of 85+ years, there are 262 males and 870 females.
Things to know
What percent of O'Fallon, MO is female?
According to the ACS survey, of the total O'Fallon, MO population of 90,802, 50.73% percent are females.
What percentage of O'Fallon, MO is male?
According to the ACS survey, of the total O'Fallon, MO population of 90,802, 49.27% percent are males.
What is the male to female ratio in O'Fallon, MO?
In O'Fallon, MO, the male to female ratio is 97.1:100 i.e. 97.1 men to 100 women (0.971).
References
- U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates