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Marin County, CA Demographics

Marin County, CA is the 26th most populous of 58 counties in California, with 262,254 residents across 520 square miles. That is about 504 people per square mile.

At the 2020 census

Population 262,254
Land area 520 sq mi
Density 504 / sq mi

Data: 2020 Census · American Community Survey 2024

How Marin County compares to the US

We're computing this county's comparison table — check back shortly. Population, land area, and density above are already exact.

Central Location: Marin County, CA

Measured from the county's main population center using 2020 census blocks.

We're computing the drive-time and radius areas around Marin County, CA — check back shortly. Meanwhile you can drop a pin anywhere in the radius tool.

Census tracts in Marin County, CA

Name Population Sq mi Per sq mi
Census Tract 1150 7,489 4.1 1,828
Census Tract 1031 7,376 15.8 467
Census Tract 1281 6,970 3.6 1,949
Census Tract 1032 6,720 1.8 3,721
Census Tract 1081 6,692 2.6 2,540
Census Tract 1212 6,478 2.4 2,756
Census Tract 1070 6,306 7.8 812
Census Tract 1101 6,176 2.6 2,340
Census Tract 1022.02 6,003 1.2 4,910
Census Tract 1261 5,955 2.0 2,911
Census Tract 1242 5,873 4.0 1,467
Census Tract 1211 5,799 1.4 4,113
Census Tract 1042 5,733 6.7 850
Census Tract 1060.02 5,666 4.3 1,308
Census Tract 1241 5,590 2.3 2,451
Census Tract 1102 5,389 3.6 1,481
Census Tract 1041.02 5,321 0.8 6,641
Census Tract 1141 5,245 3.1 1,681
Census Tract 1200.02 5,177 1.6 3,194
Census Tract 1022.03 5,174 1.1 4,924
Census Tract 1122.04 5,043 0.1 60,636
Census Tract 1060.01 5,004 4.7 1,059
Census Tract 1110.02 4,967 0.7 7,077
Census Tract 1282 4,876 1.5 3,205
Census Tract 1191 4,785 2.6 1,856
Census Tract 1170 4,713 1.0 4,496
Census Tract 1041.04 4,617 1.1 4,037
Census Tract 1121 4,611 1.1 4,056
Census Tract 1270 4,560 1.7 2,635
Census Tract 1262 4,495 1.3 3,401
Census Tract 1090.01 4,467 0.9 5,228
Census Tract 1122.02 4,445 1.5 2,907
Census Tract 1082.02 4,343 1.5 2,951
Census Tract 1250 4,211 1.0 4,396
Census Tract 1090.02 4,178 1.0 4,328
Census Tract 1130 3,910 9.8 399
Census Tract 1220 3,669 0.2 15,075
Census Tract 1050.01 3,650 0.8 4,363
Census Tract 1192.01 3,644 0.3 10,462
Census Tract 1192.02 3,567 0.8 4,614
Census Tract 1302.01 3,444 0.6 5,937
Census Tract 1330 3,215 196.1 16
Census Tract 1142 3,164 1.7 1,831
Census Tract 1050.02 3,162 2.6 1,195
Census Tract 1160 3,150 0.5 5,779
Census Tract 1041.03 3,137 1.2 2,671
Census Tract 1122.03 2,981 0.0 71,196
Census Tract 1012 2,924 4.1 721
Census Tract 1302.04 2,804 0.6 4,482
Census Tract 1011 2,682 12.8 209
Census Tract 1290 2,641 0.5 5,067
Census Tract 1082.01 2,556 0.4 6,682
Census Tract 1181 2,338 1.5 1,509
Census Tract 1021 2,251 3.6 619
Census Tract 1230 2,131 0.5 4,100
Census Tract 1321 2,111 16.6 128
Census Tract 1322 1,824 116.0 16
Census Tract 1302.03 1,687 0.3 6,282
Census Tract 1043 1,564 4.2 373
Census Tract 1200.01 1,374 0.2 6,018
Census Tract 1110.01 1,209 0.2 6,340
Census Tract 1311 1,065 49.3 22

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About this page

This page shows demographics for a US county from the 2020 census and the American Community Survey: population, land area, density, urban share, and how the county compares to national averages for income, housing, age, and more.

Counties subdivide into census tracts, listed below with their populations. The drive-time and radius tables measure the population around the county's main population center.

Read how BlockAtlas computes population within an area →