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St. Clair County, AL Demographics

St. Clair County, AL is the 16th most populous of 67 counties in Alabama, with 91,124 residents across 632 square miles. That is about 144 people per square mile.

At the 2020 census

Population 91,124
Land area 632 sq mi
Density 144 / sq mi

Data: 2020 Census · American Community Survey 2024

How St. Clair 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: St. Clair County, AL

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

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

Census tracts in St. Clair County, AL

Name Population Sq mi Per sq mi
Census Tract 401.07 5,901 10.9 540
Census Tract 405.06 5,659 17.7 320
Census Tract 405.04 5,436 20.5 265
Census Tract 401.04 5,400 4.5 1,212
Census Tract 401.08 5,225 15.9 329
Census Tract 404.01 5,078 79.6 64
Census Tract 401.10 4,967 12.7 391
Census Tract 405.03 4,780 48.6 98
Census Tract 401.05 4,465 42.6 105
Census Tract 404.02 3,923 67.1 58
Census Tract 402.10 3,585 12.5 286
Census Tract 402.07 3,381 17.6 192
Census Tract 402.09 3,312 33.1 100
Census Tract 405.07 3,303 18.3 180
Census Tract 402.13 3,249 17.3 188
Census Tract 402.11 3,072 5.8 532
Census Tract 403.01 2,876 67.9 42
Census Tract 401.09 2,819 20.0 141
Census Tract 402.06 2,772 18.8 147
Census Tract 403.02 2,771 62.1 45
Census Tract 402.08 2,589 3.1 843
Census Tract 402.12 2,529 4.8 530
Census Tract 405.05 2,154 9.9 217
Census Tract 405.08 1,857 20.3 92

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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 →