County tax profile · 2026 · Census ACS + IRS data

Property Tax & Income in Rock County, Wisconsin

Rock County has an effective property tax rate of 1.60%. On the median home value of $231,600, that's roughly $3,703 per year. Median household income is $75,673.

Effective Property Tax Rate1
1.60%
median tax $3,703 ÷ median home $231,600
Median Home Value1
$231,600
owner-occupied
Median Household Income1
$75,673
per-capita $38,536
Est. Annual Tax on Median Home1
$3,703
at 1.60% 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.

MetricRock CountyWisconsin (state context)
Effective property tax rate11.60%1.36%
Median home value1$231,600
State income tax3top rate 7.65%top rate 7.65%
State sales tax35.72% combined5.72% 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 Rock County, WI

Rock County's 1.599% effective property tax rate sits well above Wisconsin's 1.362% statewide median, and it ranks seventh among the state's 72 counties — a notably heavy rate by state standards. That rate also towers over the national median of 0.794%. Still, the tax bill itself depends heavily on what you buy: with a median home value of $231,600, the median annual real-estate tax comes to $3,703. Buyers around Janesville, the county's largest city, can weigh that against a median household income of $75,673 and per-capita income of $38,536. The result is a market where homes cost less than in many parts of the country, but the tax rate runs high, so a comparable house here can carry a larger annual bill than the same price would elsewhere.

Frequently asked questions

What is the property tax rate in Rock County, WI?
The effective rate is 1.60% — meaning the median tax bill equals about 1.60% of the median home value.
How much are property taxes on a median home?
On the median home ($231,600), the estimated annual bill is about $3,703.
Is Rock County's rate high or low?
Compare it to the state median of 1.36% 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 Rock 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 Rock 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.