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County tax profile · 2026 · Census ACS + IRS data

Property Tax & Income in Ada County, Idaho

Ada County has an effective property tax rate of 0.52%. On the median home value of $512,300, that's roughly $2,655 per year. Median household income is $91,502.

Effective Property Tax Rate1
0.52%
median tax $2,655 ÷ median home $512,300
Median Home Value1
$512,300
owner-occupied
Median Household Income1
$91,502
per-capita $49,757
Est. Annual Tax on Median Home1
$2,655
at 0.52% 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.

MetricAda CountyIdaho (state context)
Effective property tax rate10.52%0.45%
Median home value1$512,300—
State income tax3top rate 5.30%top rate 5.30%
State sales tax36.03% combined6.03% 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 Ada County, ID

Buying in Ada County means weighing a higher-than-average price tag against a tax bill that stays fairly contained. The median home here runs $512,300, well above what many Idaho markets ask, and the county's 0.518% effective rate sits above the statewide median of 0.446%. That combination still yields a median annual property tax of $2,655 — a figure that looks tame next to the national median rate of 0.794%. Households earning the median $91,502 would devote roughly 2.9% of that income to property taxes each year. Among Idaho's 44 counties, Ada ranks 11th by rate, placing it in the higher half without reaching the top tier. Boise anchors the county, with Meridian and Eagle rounding out its main communities. For a buyer, the trade-off is clear: expect to pay more for the house itself, but the ongoing tax drag stays below what many other parts of the country impose.

Frequently asked questions

What is the property tax rate in Ada County, ID?
The effective rate is 0.52% — meaning the median tax bill equals about 0.52% of the median home value.
How much are property taxes on a median home?
On the median home ($512,300), the estimated annual bill is about $2,655.
Is Ada County's rate high or low?
Compare it to the state median of 0.45% 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 Ada 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 Ada 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.