Population
Population
topographic
Population

Marin County

262,321
Total Population in 2020
In 2020, Marin County was home to 262,321 people. Residents were a majority working age, while those 65 and older were a larger segment of the county than those under 18. The population was a majority white, with more women than men.

Most Populous Demographics

CategoryDemographicTotalPercentage
Age18-64150,20457%
SexFemale133,72851%
Race and Hispanic or LatinoWhite (Not Hispanic or Latino)173,14966%

Age

46.5
Median Age
In 2020, Marin County's population was a majority working-age adults, while those 65 and older were a moderately larger share of the county than those under age 18. Looking at 10-year age ranges, 50-59 was the largest group.

Population by Age Range

010k20k30k40k0-910-1920-2930-3940-4950-5960-6970-7980+10%13%8%11%14%15%14%11%5%
010k20k30k40k10%13%8%11%14%15%14%11%5%0-910-1920-2930-3940-4950-5960-6970-7980+
/View Population by Age Range dynamic table

Population by Age Group

57%18-64
    52,870
    Under 18
    150,204
    18-64
    59,247
    65 and over
/View Population by Age Group dynamic table

Table: Population by Age Range

Age RangePopulation in Marin County
TotalPercentage
0-925,70410%
10-1932,86813%
20-2921,6968%
30-3928,77111%
40-4935,62914%
50-5939,97615%
60-6936,10114%
70-7927,55011%
80+14,0265%

Table: Population by Age Group

Age GroupPopulation in Marin County
TotalPercentage
Under 1852,87020%
18-64150,20457%
65 and over59,24723%
* For both charts above, the data is collected from the U.S. Census Bureau Decennial Data 2020, Demographic and Housing Characteristics File (DHC), P12 Sex by Age for Selected Age Categories.

Sex and Age

In 2020, females outnumbered males by a moderate amount in Marin County. Females 50-59 were the largest group by age, followed by males 50-59 and females 60-69. The biggest gap was in the 80-and-older age group, where females were the larger share.

Population by Sex

51%Female
    128,593
    Male
    133,728
    Female
/View Population by Sex dynamic table

Population by Sex and Age

05.5k11k16.5k22k0-910-1920-2930-3940-4950-5960-6970-7980+13,15116,92911,27214,48317,37519,66017,14512,7055,87312,55315,93910,42414,28818,25420,31618,95614,8458,153
05.5k11k16.5k22k0-910-1920-2930-3940-4950-5960-6970-7980+13,15116,92911,27214,48317,37519,66017,14512,7055,87312,55315,93910,42414,28818,25420,31618,95614,8458,153
22k16.5k11k5.5k05.5k11k16.5k22k0-910-1920-2930-3940-4950-5960-6970-7980+13,15116,92911,27214,48317,37519,66017,14512,7055,87312,55315,93910,42414,28818,25420,31618,95614,8458,153
/View Population by Sex and Age dynamic table
Male
Female

Table: Population by Sex

SexMarin County
TotalPercentage
Male128,59349%
Female133,72851%

Table: Population by Sex and Age

Sex and AgeMarin County
TotalPercentage
Male128,59349%
Male: 0-913,1515%
Male: 10-1916,9296%
Male: 20-2911,2724%
Male: 30-3914,4836%
Male: 40-4917,3757%
Male: 50-5919,6607%
Male: 60-6917,1457%
Male: 70-7912,7055%
Male: 80+5,8732%
Female133,72851%
Female: 0-912,5535%
Female: 10-1915,9396%
Female: 20-2910,4244%
Female: 30-3914,2885%
Female: 40-4918,2547%
Female: 50-5920,3168%
Female: 60-6918,9567%
Female: 70-7914,8456%
Female: 80+8,1533%
* For both charts above, the data is collected from the U.S. Census Bureau Decennial Data 2020, Demographic and Housing Characteristics File (DHC), P12 Sex by Age for Selected Age Categories.

Race and Hispanic or Latino

66%
White (Not Hispanic or Latino)
In 2020, Marin County had a majority white population. Hispanic residents also made up a notable segment of the county, while other/multiracial and Asian people were the next largest groups.

Population by Race and Hispanic or Latino

045k90k135k180kWhite*Black or African American*American Indian / Alaska Native*Asian*Native Hawaiian / Pacific Islander*Other / Multi-racial*Hispanic or Latino (any race)66%2%<1%6%<1%6%19%
045k90k135k180kWhite*Black or African American*American Indian / Alaska Native*Asian*Native Hawaiian / Pacific Islander*Other / Multi-racial*Hispanic or Latino (any race)66%2%<1%6%<1%6%19%
045k90k135k180kWhite*Black or African American*American Indian / Alaska Native*Asian*Native Hawaiian / Pacific Islander*Other / Multi-racial*Hispanic or Latino (any race)66%2%<1%6%<1%6%19%
/View Population by Race and Hispanic or Latino dynamic table

Table: Population by Race and Hispanic or Latino

Race and Hispanic or LatinoPopulation in Marin County
TotalPercentage
White173,14966%
Black or African American6,1202%
American Indian / Alaska Native555<1%
Asian16,1756%
Native Hawaiian / Pacific Islander457<1%
Other / Multi-racial16,4556%
Hispanic or Latino (any race)49,41019%
* Categorized as Not Hispanic. This means that all the racial groups marked with an asterisk — White, Black or African American, American Indian / Alaska Native, Asian, Native Hawaiian / Pacific Islander, and Other / Multi-racial — do not include individuals who identify as Hispanic or Latino. The "Hispanic or Latino (any race)" category is separate, as Hispanic/Latino is considered an ethnicity rather than a racial category. For the chart above, the data is collected from the U.S. Census Bureau Decennial Data 2020, Demographic and Housing Characteristics File (DHC), P5 Hispanic or Latino Origin by Race.