Average mortgage payment in Ada County, ID (2026)
The average mortgage payment in Ada County on a median-priced home (~$490,000) is roughly $3,685/month — assuming 10% down at a 6.85% 30-year fixed rate and Idaho's 0.69% 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 $157,948. County population is roughly 494,967.
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How Ada County compares to Idaho
The typical home in Ada County is 10% above the statewide median of $445,000 in Idaho. Property tax is set at the state's effective rate of 0.69% — 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 Ada County?+
On a median Ada County home (~$490,000) at a 6.85% 30-year fixed rate with 10% down, all-in PITI runs about $3,685/month, including ~$282 in property tax.
What income do I need to buy a home in Ada County?+
Using the 28% front-end DTI rule, you'd need roughly $157,948 in annual gross household income to comfortably carry the median Ada County home.
How does Ada County compare to the rest of Idaho?+
Ada County's median home ($490,000) is 10% above the Idaho median of $445,000.
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.