Jefferson County, CO Population

Overview

580,130

Total Population

40.2

Median age

49.79%

Female population %

100.8:100

Gender ratio (M:F)

30-34 years

Largest age group

48.3

Total dependency ratio

White

Largest racial group

91,053

Hispanic population

Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

TABLE OF CONTENTS

Age

Jefferson County's population is old compared to the rest of the country:

The median age in Jefferson County is 40.2, compared to 38.8 nationwide, according to the American Community Survey 2017 - 2021 5 Year estimates.
Jefferson County's population under 18 was 19.59%, compared to the 22.51% nationwide.
Jefferson County's elderly or the senior population (over 65 age) was 16.53% as compared to 16.04% nationwide.
Of the total population in Jefferson County, 16.04% were under the age of 15, 18.22% aged 15 to 29, 49.21% aged 30 to 64, 14.63% aged 65 to 84, and 1.90% were 85 years of age and older.

There are 2,396 less females than males in Jefferson County:

The female percentage in the USA is 50.50% while the male percentage is 49.50%, compared to 49.79% females and 50.21% males in Jefferson County, CO.
The Jefferson County, CO gender ratio is 100.8:100 i.e. 100.8 men to 100 women (1.008).
For male population, the largest age group is 30-34 years with a population of 23,725.
For the female population, the largest age group is 55-59 years with a population of 21,742.

Jefferson County's population has become increasingly diverse:

Racial distribution of Jefferson County population: 86.04% are White, 1.13% are Black or African American, 0.65% are American Indian and Alaska Native, 2.83% are Asian, 0.07% are Native Hawaiian and other Pacific Islander, 2.42% are some other race and 6.86% are multiracial.
Jefferson County's racial breakdown clearly shows that there is an absolute majority of White population in the county.
By ethnicity, 91,053 is Hispanic or Latino (of any race), and 489,077 (84.30% of the total population) is Non-Hispanic.
The largest racial group in Jefferson County is White with a population of 499,171 (86.04% of the total population).

Jefferson County's population has already reached its peak and is showing a trend of decline:

The peak population was 583,050 in the year 2020
From 2000 to 2010, Jefferson County's population increased by 9,005 (1.71%), as compared to the national growth of 9.63%.
From 2010 to 2020, Jefferson County's population increased by 47,483 (8.87%), according to Census Bureau's Population Estimates Program. For the same period, the rate of growth for the United States was 7.17%.
Between the year 2000 and 2022, Jefferson County's population was lowest in year 2005 at 524,695.