Marin County Population

1850–2026

251.68K

2026 projection

3.7% since 2020 (decrease)

050K100K150K200K250K300K186018801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for Marin County. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
2026251,684-2,0100.79%
2025253,694-2,0100.79%
2024255,704+2610.10%
2023255,443-1,5950.62%
2022257,038-2,3110.89%
2021259,349-1,9880.76%
2020261,337+2,2520.87%
2019259,085-1,0060.39%
2018260,091+1160.04%
2017259,975-7470.29%

Showing 10 of 32 years.

Marin County Demographics

47.4median age

Median age

Female49 yrs
Male45.9 yrs

Adults

207,983
61,345 seniors (65+) · 29% of adults146,638 other adults

Sex

Female 50.8% · 131,092Male 49.2% · 126,877

Population by age

MaleFemale85+ years, male: 2,81885+ years, female: 4,52580–84 years, male: 3,76980–84 years, female: 4,29875–79 years, male: 5,44975–79 years, female: 6,71870–74 years, male: 7,04070–74 years, female: 9,19765–69 years, male: 8,44465–69 years, female: 9,08760–64 years, male: 8,81460–64 years, female: 8,92955–59 years, male: 9,99755–59 years, female: 10,90050–54 years, male: 9,78050–54 years, female: 10,06145–49 years, male: 8,97545–49 years, female: 8,68640–44 years, male: 8,75240–44 years, female: 7,92135–39 years, male: 6,66835–39 years, female: 7,03730–34 years, male: 6,07830–34 years, female: 5,53825–29 years, male: 5,43225–29 years, female: 4,84020–24 years, male: 6,28520–24 years, female: 6,20715–19 years, male: 8,27415–19 years, female: 7,83510–14 years, male: 7,43710–14 years, female: 7,3365–9 years, male: 7,0155–9 years, female: 6,5020–4 years, male: 5,8500–4 years, female: 5,47585+80–8475–7970–7465–6960–6455–5950–5445–4940–4435–3930–3425–2920–2415–1910–145–90–45K5K10K10K

Hover or tap an age group to see exact counts. Use the up and down arrow keys to inspect age groups.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 2,580 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

Marin County Income

$149,091median household income

Median household income

$149,091

Half of households earn more, half earn less

Median earnings

$83,637

Typical yearly pay for a worker 25 or older.

Poverty rate

8.3%

About 1 in 12 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

Marin County Marital Status

51% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married51%54%49%
Never married31%33%28%
Divorced12%9%14%
Widowed5%2%8%
Separated1%1%1%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201

Sources

8 sources, all from the U.S. Census Bureau

Population

American Community Survey, 2024 5-year