Average mortgage payment in San Mateo County, CA (2026)
The average mortgage payment in San Mateo County on a median-priced home (~$900,000) is roughly $7,005/month — assuming 10% down at a 6.85% 30-year fixed rate and California's 1.25% 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 $300,219. County population is roughly 764,442.
Adjust the scenario
How San Mateo County compares to California
The typical home in San Mateo County is 17% above the statewide median of $770,000 in California. Property tax is set at the state's effective rate of 1.25% — 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 San Mateo County?+
On a median San Mateo County home (~$900,000) at a 6.85% 30-year fixed rate with 10% down, all-in PITI runs about $7,005/month, including ~$938 in property tax.
What income do I need to buy a home in San Mateo County?+
Using the 28% front-end DTI rule, you'd need roughly $300,219 in annual gross household income to comfortably carry the median San Mateo County home.
How does San Mateo County compare to the rest of California?+
San Mateo County's median home ($900,000) is 17% above the California median of $770,000.
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.