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St. Charles County, MO Demographics

St. Charles County, MO is the 3rd most populous of 115 counties in Missouri, with 405,262 residents across 561 square miles. That is about 723 people per square mile.

At the 2020 census

Population 405,262
Land area 561 sq mi
Density 723 / sq mi

Data: 2020 Census · American Community Survey 2024

How St. Charles 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. Charles County, MO

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

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

Census tracts in St. Charles County, MO

Name Population Sq mi Per sq mi
Census Tract 3120.96 9,026 3.1 2,899
Census Tract 3121.93 8,915 4.6 1,954
Census Tract 3113.12 7,417 2.5 2,953
Census Tract 3111.22 7,301 1.8 4,001
Census Tract 3117.32 7,074 2.1 3,433
Census Tract 3120.03 6,938 23.0 301
Census Tract 3111.24 6,907 4.5 1,525
Census Tract 3111.53 6,886 2.5 2,798
Census Tract 3113.22 6,787 3.9 1,755
Census Tract 3111.03 6,533 8.3 789
Census Tract 3120.95 6,470 14.7 439
Census Tract 3119.04 6,462 2.7 2,392
Census Tract 3111.51 6,413 2.7 2,411
Census Tract 3121.92 6,266 5.6 1,117
Census Tract 3118.01 6,250 6.2 1,015
Census Tract 3118.02 6,220 4.2 1,485
Census Tract 3119.07 6,217 1.2 5,324
Census Tract 3102.01 6,187 2.1 2,880
Census Tract 3112.03 6,154 1.6 3,893
Census Tract 3114.22 6,035 1.7 3,477
Census Tract 3119.03 6,030 2.2 2,743
Census Tract 3116.02 5,980 3.3 1,804
Census Tract 3117.35 5,970 1.2 4,794
Census Tract 3108.02 5,946 1.7 3,501
Census Tract 3113.11 5,880 1.1 5,401
Census Tract 3120.94 5,765 3.7 1,567
Census Tract 3110.04 5,736 1.0 5,535
Census Tract 3106.02 5,680 2.0 2,906
Census Tract 3124 5,555 2.3 2,389
Census Tract 3112.11 5,470 1.5 3,715
Census Tract 3111.54 5,387 1.2 4,395
Census Tract 3109.02 5,318 1.6 3,384
Census Tract 3111.14 5,253 2.2 2,397
Census Tract 3107 5,232 1.3 4,079
Census Tract 3119.09 5,174 2.5 2,076
Census Tract 3122.04 5,155 100.2 51
Census Tract 3122.08 5,118 1.2 4,446
Census Tract 3117.12 4,889 1.9 2,561
Census Tract 3113.91 4,831 0.8 5,853
Census Tract 3122.06 4,721 41.4 114
Census Tract 3111.50 4,720 1.2 3,902
Census Tract 3113.31 4,631 1.3 3,699
Census Tract 3111.52 4,590 1.8 2,579
Census Tract 3117.39 4,551 1.1 4,051
Census Tract 3122.09 4,489 3.1 1,464
Census Tract 3111.46 4,488 1.2 3,619
Census Tract 3119.08 4,475 4.0 1,115
Census Tract 3117.38 4,465 0.8 5,625
Census Tract 3111.45 4,388 1.6 2,726
Census Tract 3111.48 4,317 7.0 620
Census Tract 3122.07 4,286 1.9 2,273
Census Tract 3110.01 4,271 2.1 2,042
Census Tract 3112.12 4,243 1.2 3,679
Census Tract 3117.34 4,233 1.1 3,686
Census Tract 3120.02 4,221 3.4 1,246
Census Tract 3112.96 4,110 1.2 3,403
Census Tract 3103.01 4,068 1.3 3,240
Census Tract 3109.03 4,051 1.0 4,205
Census Tract 3111.47 4,031 1.0 4,045
Census Tract 3103.02 3,980 1.0 4,021
Census Tract 3105.01 3,872 0.9 4,426
Census Tract 3111.49 3,835 1.3 2,984
Census Tract 3112.94 3,826 1.0 3,891
Census Tract 3117.21 3,765 1.3 2,966
Census Tract 3106.01 3,757 0.7 5,236
Census Tract 3112.21 3,613 1.2 3,092
Census Tract 3102.02 3,602 1.4 2,516
Census Tract 3111.32 3,499 5.3 664
Census Tract 3121.94 3,488 2.1 1,656
Census Tract 3117.37 3,461 0.8 4,096
Census Tract 3121.95 3,318 2.1 1,572
Census Tract 3120.01 3,228 27.9 116
Census Tract 3116.04 3,164 1.1 2,753
Census Tract 3110.03 3,149 0.9 3,512
Census Tract 3116.03 2,780 0.8 3,657
Census Tract 3123 2,730 0.7 4,081
Census Tract 3108.01 2,487 1.1 2,168
Census Tract 3105.02 2,467 0.8 2,936
Census Tract 3109.01 2,375 0.6 3,704
Census Tract 3117.33 2,272 0.9 2,622
Census Tract 3115 2,205 56.5 39
Census Tract 3117.40 2,096 1.2 1,722
Census Tract 3101 2,064 108.6 19
Census Tract 3104 2,035 0.6 3,149
Census Tract 9800 12 29.2 0

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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 →