Average mortgage payment in St. Louis County, MO (2026)
The average mortgage payment in St. Louis County on a median-priced home (~$320,000) is roughly $2,558/month — assuming 10% down at a 6.85% 30-year fixed rate and Missouri's 0.97% effective property tax rate (full PITI).
To carry that payment under the standard 28% front-end DTI rule, you'd need an annual household income near $109,621. County population is roughly 1,004,125.
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How St. Louis County compares to Missouri
The typical home in St. Louis County is 33% above the statewide median of $240,000 in Missouri. Property tax is set at the state's effective rate of 0.97% — local millage and special assessments vary by county, but this is the right starting point.
The payment above bakes in principal, interest, property tax, and homeowners insurance — it does not include HOA dues or mortgage insurance (PMI). PMI kicks in automatically when down payment is below 20% on a conventional loan. For a full breakdown, run your own numbers in the main calculator.
Frequently asked questions
What is the average mortgage payment in St. Louis County?+
On a median St. Louis County home (~$320,000) at a 6.85% 30-year fixed rate with 10% down, all-in PITI runs about $2,558/month, including ~$259 in property tax.
What income do I need to buy a home in St. Louis County?+
Using the 28% front-end DTI rule, you'd need roughly $109,621 in annual gross household income to comfortably carry the median St. Louis County home.
How does St. Louis County compare to the rest of Missouri?+
St. Louis County's median home ($320,000) is 33% above the Missouri median of $240,000.
Does this include HOA fees or PMI?+
No. HOA dues vary too widely to assume a default — add them directly to the payment. PMI applies when you put less than 20% down on a conventional loan; the main calculator factors it in automatically.