• county
  • FIPS 06041
  • Largest town: San Rafael

Marin County, California

Marin County had 256,400 residents in the Census Vintage 2024 estimate, on 520.1 square miles of land. It ranks 26th of 58 in California by population and 55th by land area.

Population
256,400
#26 of 58 in California · #286 in US
Area
520.1 sq mi
#55 of 58 in California · #2,004 in US
Density
493 / sq mi
#13 of 58 in California · #283 in US
Median household income
$139,197
#3 of 58 in California · #12 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Marin County within California. Pin: Sacramento.

Measure from here

Tools and pages that start from Marin County

Marin County population, land area and income

Marin County had 256,400 residents in the Census Vintage 2024 estimate, on 520.1 square miles of land. It ranks 26th of 58 in California by population and 55th by land area. That works out to 492.9 people per square mile, 5.1 times the US average of 96.3, and in the top tenth nationally.

The median county-equivalent in California has 187,274 residents; Marin County is somewhat larger.

Its SAIPE 2023 median household income of $139,197 is in the top tenth among 3,143 counties with an estimate.

National rank among 3,144

Population

256,400

3144th1st

286th of 3,144 (US)

Land area

520 sq mi

3144th1st

2004th of 3,144 (US)

Density

492.9 / sq mi

3144th1st

283rd of 3,144 (US)

Median household income

$139,197

3143rd1st

12th of 3,143 (US)

Rank within California (58)

Population

256,400

58th1st

26th of 58 (CA)

Land area

520 sq mi

58th1st

55th of 58 (CA)

Density

492.9 / sq mi

58th1st

13th of 58 (CA)

Median household income

$139,197

58th1st

3rd of 58 (CA)

How Marin County's population changed since 2020

Marin County lost 4,941 residents between the July 2020 and July 2024 estimates, a drop of 1.9%. That ranks 40th of 58 in California for growth. The median California county changed by -0.6%, and the state as a whole by -0.2%.

Since the April 2020 estimates base, Marin County recorded 9,304 births and 9,235 deaths, a natural change of +69. Net international migration added +6,089 and net domestic migration, people moving to or from other US counties, came to -12,150. The largest single component was domestic migration, which removed 12,150 people.

261.3k2020259.3k2021257.1k2022255.7k2023256.4k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
9,304
Deaths
9,235
Net international migration
+6,089
Net domestic migration
-12,150
Change, July 2023 to July 2024
+694

Where Marin County is

The Census internal point of Marin County is at 38.051400, -122.746400. It sits in UTM zone 10N. The map shades California's 58 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Marin County outlined. Dots are towns of 1,000+ people with residents in it.

Los Angeles County: -2.4%Kings County: +1.4%Sierra County: -3.6%Riverside County: +4.3%Santa Barbara County: -0.8%San Bernardino County: +1.4%Nevada County: -0.1%Santa Clara County: +0.1%Yuba County: +6.7%Fresno County: +1.4%Plumas County: -4.7%Monterey County: -1.0%Amador County: +3.6%Alameda County: -1.9%Tulare County: +2.0%San Joaquin County: +4.5%Alpine County: -6.8%Siskiyou County: -3.4%Butte County: -0.9%Kern County: +1.8%San Diego County: -0.1%Sacramento County: +1.5%Ventura County: -1.0%Yolo County: +3.4%Lake County: -0.6%Napa County: -3.4%Tehama County: -1.9%San Francisco County: -5.4%El Dorado County: +0.8%Calaveras County: +2.5%Inyo County: -2.7%Shasta County: -0.6%Lassen County: -12.3%San Luis Obispo County: -0.0%Mariposa County: -0.5%Trinity County: -2.8%Contra Costa County: +0.6%Mendocino County: -2.4%Imperial County: +1.1%Santa Cruz County: -3.4%Placer County: +6.9%Orange County: -0.5%San Benito County: +7.2%Marin County: -1.9%San Mateo County: -2.6%Colusa County: +0.9%Del Norte County: -2.2%Solano County: +0.5%Glenn County: -2.0%Tuolumne County: -2.7%Sonoma County: -0.6%Humboldt County: -2.9%Mono County: -1.8%Stanislaus County: +0.6%Merced County: +4.9%Sutter County: -0.9%Madera County: +5.8%Modoc County: -2.1%
Change 2020 to 2024
  1. < -2.7%
  2. < -1.0%
  3. < -0.0%
  4. < +1.5%
  5. ≥ +1.5%
no data

Orange pin: Marin County internal point. Dark pin: Sacramento.

Internal point

Decimal
38.051400, -122.746400
DMS
38°03'5.04"N 122°44'47.04"W
UTM
10N 522249.9E 4211548.3N
Geohash
9qb8qz4c3
Plus code
84CV3723+HC

Towns in Marin County

11 incorporated places of 1,000+ people have residents in Marin County, 189,495 people together, or 74% of the county. Each figure counts only the part of the town inside Marin County; towns marked "part" extend into another county. The largest is San Rafael with 59,961.

  1. 01San Rafael59,961
  2. 02Novato52,311
  3. 03Mill Valley13,904
  4. 04Larkspur12,807
  5. 05San Anselmo12,645
  6. 06Corte Madera10,006
  7. 07Tiburon8,933
  8. 08Fairfax7,476
  9. 09Sausalito7,075
  10. 10Ross2,297
  11. 11Belvedere2,080
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Marin County

The Census 2024 county adjacency file lists 4 neighbors for Marin County. The most populous is Contra Costa County, CA, with 1,172,607 residents. Distances run between Census internal points in a straight line.

Distance to Sacramento and the nearest big city

Sacramento is 77.0 miles ENE of Marin County's internal point in a straight line. The nearest place of 100,000 or more is Richmond, CA (population 115,353), 22.1 miles away. The nearest place of 10,000 or more is San Anselmo, CA (population 12,645), 10.7 miles away.

Marin County FIPS code

The FIPS code of Marin County is 06041: state code 06 for California plus county code 041. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $139,197.

Questions people ask

What is the population of Marin County, California?

The Census Vintage 2024 estimate for July 1, 2024 is 256,400. That is down 4,941 people (1.9%) from the July 2020 estimate of 261,341.

What is the FIPS code of Marin County?

06041. The first two digits (06) are California; the last three (041) identify the county.

What is the largest town in Marin County?

San Rafael, with 59,961 residents inside Marin County in 2024.

Which counties border Marin County?

4 county-equivalents border it in the Census 2024 adjacency file: Contra Costa County, CA; San Francisco County, CA; Sonoma County, CA; Solano County, CA.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.