Property Tax in Ada County, Idaho
In Ada County, Idaho, the typical homeowner pays $2,643 a year in property taxes on a home worth a median of $476,000. The figures on this page are the Census Bureau's published medians (US Census Bureau, American Community Survey (ACS) 5-year estimates, 2023), shown exactly as released.
What the Ada County numbers mean
A median is the middle household: half of owner-occupied households in Ada County pay more than $2,643, and half pay less. Your own bill is set by your home's assessed value, the exemptions you qualify for, and the local taxing districts your property sits in — so individual bills vary widely around the median.
Dividing the median tax by the median home value gives a derived effective rate of 0.56% for Ada County. It is an estimate built from two survey medians, not the county's official rate, but it is a fair way to compare the local tax burden with other counties where home values are very different.
The key figures for Ada County
| Measure | Ada County |
|---|---|
| Median real estate taxes paid per year | $2,643 |
| Median home value | $476,000 |
| Derived effective rate* | 0.56% |
| Equivalent monthly tax | $220 |
| Tax per $100,000 of value (derived) | $555 |
| Illustrative tax on a $400,000 home (derived rate) | $2,220 |
For context, the Idaho medians are $2,006 of tax on $376,000 of value, and the US medians are $2,969 on $303,400. *Derived figures are estimates from Census medians, not official rates.
Ada County at a glance
- Median tax rank in Idaho: #1 of 44 counties
- Median home value rank in Idaho: #4 of 44
- Population rank in Idaho: #1 of 44 (508,052 residents)
- Population density rank: #1 of 44 (483 people per square mile)
- Land area rank in Idaho: #31 of 44 (1,052 sq mi, 1.3% of the combined county land area)
- Median tax as a monthly figure: $220; per $1,000 of home value: $0.56
How Ada County compares
Of the 44 Idaho counties with published data, 0 have a higher median property tax bill than Ada County's $2,643, putting the county at #1 in the state. Its bill is about 32% higher than the state median of $2,006 and about 11% lower than the national median of $2,969.
Rates and values pull in opposite directions: an expensive housing market can produce big bills at ordinary rates. Here the derived rate is 0.56%, versus 0.98% derived nationally, and the median home value ranks #4 within Idaho.
Some extra context for Ada County: the median bill works out to about $220 a month, and the derived rate equals roughly $555 of tax per $100,000 of home value. The county is home to 508,052 people — the #1 most populous county in Idaho, spread over 1,052 square miles, a density of about 483 people per square mile. Its median home value, $476,000, ranks #4 among the state's 44 counties with data.
Nationally, Ada County's median bill of $2,643 ranks #610 of 3133 counties with published data — inside the top 19% of counties by tax paid. The county accounts for about 26.8% of Idaho's population, its median home value is about 27% above the state median, and at the derived rate the median home would hand over roughly 5.55% of its value in tax across a decade. Within the state, the distance from Ada County to the most expensive county, Ada County ($2,643), is $0 a year.
Counties nearest Ada County in the Idaho ranking
| County | Median tax paid | Median home value | Derived rate* |
|---|---|---|---|
| Blaine County, ID | $2,563 | $663,800 | 0.39% |
| Nez Perce County, ID | $2,529 | $291,300 | 0.87% |
How the tax is worked out
The bill is built in stages. First the assessor puts a market value on the property. Exemptions — a homestead exemption above all — then reduce the taxable amount. Finally the combined local rate is applied. To see the scale: at the county's derived rate of 0.56%, each $100,000 of value corresponds to about $555 of tax a year, and a $400,000 home to roughly $2,220. Real bills use the official assessment and district rates, not this derived figure, so treat the example as a sense of scale only.
Checking your assessment in Ada County
Most successful appeals are won on facts, not arguments. Start with the property record card held by the Ada County assessor: wrong square footage, an extra room, or a missing homestead exemption are common and fixable. Next, line your assessed value up against recent sales of genuinely similar homes nearby. Many disputes end at an informal conversation with the assessor's office; if yours does not, file the formal appeal with the review board named on your notice before its deadline, evidence attached, and keep paying the bill in the meantime so penalties do not build up.
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Frequently asked questions
What is the median property tax in Ada County, Idaho?
The median real estate tax paid in Ada County, Idaho is $2,643 per year, on a median home value of $476,000 (US Census Bureau, American Community Survey (ACS) 5-year estimates, 2023).
What is the effective property tax rate in Ada County, Idaho?
Dividing Ada County's median tax bill ($2,643) by its median home value ($476,000) gives a derived effective rate of 0.56%. This is an estimate computed from two Census survey medians — it is not the county's official tax rate.
How does Ada County compare with the rest of Idaho?
By median taxes paid, Ada County stands at #1 among the 44 Idaho counties the Census publishes figures for. Its $2,643 median bill is about 32% higher than the state median ($2,006), and 0 counties in the state record a higher median.
How are property taxes calculated in Ada County, Idaho?
The assessor estimates your property's market value; exemptions (such as a homestead exemption) reduce the taxable amount; and the result is multiplied by the combined rates of the local taxing districts — county, municipality, school district and any special districts. In Ada County, the median outcome of that process is a bill of $2,643 on a median home value of $476,000.
Can I appeal my property tax assessment in Ada County, Idaho?
You can. Pull your property record card from the Ada County assessor, verify its details, and compare the assessed value against similar homes that sold recently. If the value still seems too high, submit a formal appeal to the board named on your notice before the stated deadline — usually a 30-to-90-day window.