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County tax profile · 2026 · Census ACS + IRS data

Property Tax & Income in St. Charles County, Missouri

St. Charles County has an effective property tax rate of 1.08%. On the median home value of $320,800, that's roughly $3,480 per year. Median household income is $104,692.

Effective Property Tax Rate1
1.08%
median tax $3,480 ÷ median home $320,800
Median Home Value1
$320,800
owner-occupied
Median Household Income1
$104,692
per-capita $51,051
Est. Annual Tax on Median Home1
$3,480
at 1.08% effective rate

What you'll pay, at a glance

Property taxes are the largest local tax most homeowners pay. The effective rate measures the real tax bill as a share of home value — a more useful number than the nominal “mill rate,” because assessment practices vary county to county.

MetricSt. Charles CountyMissouri (state context)
Effective property tax rate11.08%0.70%
Median home value1$320,800—
State income tax3top rate 4.80%top rate 4.80%
State sales tax38.44% combined8.44% combined

How this is calculated

The effective property tax rate is the median real-estate tax bill divided by the median home value — both for owner-occupied homes, from the U.S. Census Bureau's American Community Survey (ACS 5-year estimates)1. Median income is also from the ACS1. Federal and state income-tax figures use IRS2 and Tax Foundation3 data.

About St. Charles County, MO

Property taxes in St. Charles County run well above both the Missouri and national medians. The county's 1.085% effective rate tops Missouri's 0.705% statewide figure and the 0.794% national median, placing it fourth among the state's 115 counties. That gap shows up in actual bills: the median home value of $320,800 carries an annual real-estate tax of about $3,480. Households here earn a median of $104,692, with per-capita income at $51,051, so the tax load lands on a comparatively affluent population. Communities such as Saint Charles, O'Fallon, and Augusta sit within the county, and homeowners in these places should expect assessments that outpace what many Missourians pay. Ranking so high within the state signals that local levies — school, municipal, and county combined — are doing more heavy lifting than in most of Missouri.

Frequently asked questions

What is the property tax rate in St. Charles County, MO?
The effective rate is 1.08% — meaning the median tax bill equals about 1.08% of the median home value.
How much are property taxes on a median home?
On the median home ($320,800), the estimated annual bill is about $3,480.
Is St. Charles County's rate high or low?
Compare it to the state median of 0.70% and the national average near 1.1%.
How does the effective rate differ from my mill rate?
A mill rate is the nominal levy per $1,000 of assessed value. The effective rate reflects what you actually pay after exemptions and assessments — it's the median tax bill as a share of median home value, so it better predicts your real cost.
Will a reassessment raise my tax bill?
Not necessarily. If your home's assessed value rises, your bill can go up, but only if the mill rate and exemptions stay flat. Contact the St. Charles County assessor's office to review your current assessment.
Can I appeal my property tax assessment?
Yes. Most counties allow an appeal when you believe the assessed value exceeds the market value. File with the St. Charles County assessor within the local deadline, typically with comparable sales as evidence.
Sources
[1] U.S. Census Bureau — ACS 5-Year (2023) — Median home value (B25077), median real-estate taxes (B25103), median household income (B19013), per-capita income (B19301).
[2] IRS — Statistics of Income — County income, AGI, and real-estate taxes paid.
[3] Tax Foundation — State income, sales, corporate, and estate/inheritance tax rates.