Marin County, CA Population

Overview

262,387

Total Population

47.1

Median age

50.78%

Female population %

96.9:100

Gender ratio (M:F)

55-59 years

Largest age group

62.5

Total dependency ratio

White

Largest racial group

43,043

Hispanic population

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

TABLE OF CONTENTS

Age

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

The median age in Marin County is 47.1, compared to 38.8 nationwide, according to the American Community Survey 2017 - 2021 5 Year estimates.
Marin County's population under 18 was 19.99%, compared to the 22.51% nationwide.
Marin County's elderly or the senior population (over 65 age) was 22.36% as compared to 16.04% nationwide.
Of the total population in Marin County, 16.10% were under the age of 15, 14.50% aged 15 to 29, 47.04% aged 30 to 64, 19.66% aged 65 to 84, and 2.70% were 85 years of age and older.

There are 4,099 more females than males in Marin County:

The female percentage in the USA is 50.50% while the male percentage is 49.50%, compared to 50.78% females and 49.22% males in Marin County, CA.
The Marin County, CA gender ratio is 96.9:100 i.e. 96.9 men to 100 women (0.969).
For male population, the largest age group is 50-54 years with a population of 10,203.
For the female population, the largest age group is 55-59 years with a population of 11,302.

Marin County's population has become increasingly diverse:

Racial distribution of Marin County population: 75.32% are White, 2.28% are Black or African American, 0.38% are American Indian and Alaska Native, 6.06% are Asian, 0.16% are Native Hawaiian and other Pacific Islander, 8.02% are some other race and 7.78% are multiracial.
Marin County's racial breakdown clearly shows that there is an absolute majority of White population in the county.
By ethnicity, 43,043 is Hispanic or Latino (of any race), and 219,344 (83.60% of the total population) is Non-Hispanic.
The largest racial group in Marin County is White with a population of 197,622 (75.32% of the total population).

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

The peak population was 261,282 in the year 2020
From 2000 to 2010, Marin County's population increased by 5,306 (2.14%), as compared to the national growth of 9.63%.
From 2010 to 2020, Marin County's population increased by 8,376 (3.31%), 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, Marin County's population was lowest in year 2004 at 244,410.