Mercer County, Illinois Property Taxes
Property Taxes in Mercer County, Illinois
Median Mercer County effective property tax rate: 2.81%, significantly higher than the national median of 1.02%.
Median Mercer County home value: $150,030
Median annual Mercer County tax bill: $4,254, $1,854 higher than the national median property tax bill of $2,400.
How are property taxes in Mercer County calculated?
Property taxes in Mercer County are calculated based on the tax assessed value, which is often lower than the actual market value due to property tax exemptions such as the homestead or senior exemption.
Understanding your county's property tax system, exemptions, and reduction opportunities can lead to significant savings. Whether you live in Mercer County or another part of Mercer County, knowing local tax details benefits homeowners and investors.
Last Updated April 13, 2026
Mercer County, Illinois Property Tax Bill Calculator
$100,000
$1,500,000
$3,000,000
Median Effective Tax Rate
2.81%
Estimate Property Tax Bill
$4,216
$3,912
How Does the Mercer County Property Tax Calculator Work?
Use this Mercer County property tax calculator to estimate your annual property tax bill. Enter your property's assessed value and our calculator applies Mercer County's median effective tax rate of 2.81% to generate your estimate.
Enter your property's estimated assessed value — the figure the assessment authority assigns for tax purposes, which is typically lower than market value after applicable exemptions. Our calculator uses the median effective rate for a more accurate estimate than the statutory millage rate alone.
Your actual bill may vary based on your specific exemptions, local school district levies, and any special assessment districts that apply to your property. Mercer County's median tax rate is higher than the Illinois median tax rate of 2.33%, and the median tax bill of $4,254 is higher than the Illinois median tax bill by $1,854.
For a more precise estimate, scroll down to explore city and ZIP code-level tax rate trends across Mercer County.
Property Tax Rates Across Mercer County, Illinois
What Are Effective Property Tax Rates Across Mercer County?
Local government entities set tax rates, which vary widely across Mercer County. Each year, the county estimates its budget for public services and divides that total by the assessed value of all taxable property within its jurisdiction.
Below, compare Mercer County's effective property tax rate to other counties in Illinois or the U.S. median of 1.02%.
Mercer County's median effective rate stands at 2.81%, which is higher than the national median of 1.02%. Within Mercer County, the highest rate is found in Seaton at 3.09%, while Preemption has the lowest at 2.57%.
These variations reflect differences in local school district levies, Special service areas (SSAs) assessments, and special district bonds — which compound the base county rate.
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Mercer County Tax Rate
2.81%
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Illinois Tax Rate
2.33%
Median Effective United States Tax Rate
1.02%
Property Tax Rates Across Mercer County, Illinois
| City | 10th Percentile | 25th Percentile | Median Tax Rate | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| Aledo | 2.27% | 2.58% | 2.88% | 3.09% | 3.38% |
| Alexis | 2.43% | 2.60% | 2.83% | 2.96% | 3.06% |
| Illinois City | 2.23% | 2.46% | 2.58% | 2.68% | 2.91% |
| Joy | 2.53% | 2.75% | 2.96% | 3.17% | 3.32% |
| Keithsburg | 2.25% | 2.72% | 2.96% | 3.19% | 3.28% |
| Lynn Center | 0.81% | 2.33% | 2.59% | 2.91% | 4.62% |
| Matherville | 2.30% | 2.39% | 2.69% | 2.76% | 2.89% |
| New Boston | 2.28% | 2.53% | 2.76% | 3.07% | 3.49% |
| New Windsor | 1.82% | 2.28% | 2.59% | 2.87% | 3.05% |
| North Henderson | 2.22% | 2.63% | 2.80% | 2.96% | 3.08% |
| Preemption | 2.48% | 2.48% | 2.57% | 2.75% | 2.92% |
| Reynolds | 2.32% | 2.68% | 2.93% | 3.29% | 3.73% |
| Seaton | 2.76% | 2.91% | 3.09% | 3.16% | 3.29% |
| Sherrard | 2.06% | 2.48% | 2.63% | 2.84% | 3.10% |
| Viola | 2.11% | 2.50% | 2.72% | 2.95% | 3.14% |
| Milan | N/A | N/A | N/A | N/A | N/A |
| Orion | N/A | N/A | N/A | N/A | N/A |
| Rio | N/A | N/A | N/A | N/A | N/A |
Source: Ownwell
Property Tax Assessment Values Across Mercer County, Illinois
When examining property taxes in Mercer County, understanding the distinction between "market value" and "assessed value" is crucial.
The market value is what a willing buyer would pay to a willing seller in an open and competitive market, often influenced by location, property condition, and economic market trends. The Mercer County assessment office estimates the market value for tax purposes.
The assessed value is the market value minus any applicable exemptions or limits determined by local laws and offerings. The tax assessed value is the figure used to calculate your property taxes or the amount multiplied by your tax rate to get your tax bill.
Assessment notices:
In Mercer County, assessment notices are sent in the spring each year. They'll typically reach your mailbox by the middle of May.
Each property owner receives an assessment notice that contains both the market value and assessed value, along with an estimate of your property tax bill. Mercer County’s median tax bill is $4,254, compared with the national median property tax bill of $2,400. Tax bills range significantly across the county, with the 25th percentile at $2,247 and the 90th percentile at $10,539. Seaton has the highest median home price at $207,068.
Property Tax Assessment Values Across Mercer County, Illinois
Source: Ownwell
$103,635
$155,352
$207,068
Median Mercer County Market Value
$150,030
Median Illinois Market Value
$227,888
Median United States Market Value
$235,294
Property Tax Assessment Values Across Mercer County, Illinois
| City | 10th Percentile | 25th Percentile | Median Home Price | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| Aledo | $24,750 | $76,485 | $146,985 | $244,298 | $375,543 |
| Alexis | $49,839 | $108,900 | $177,477 | $306,612 | $450,021 |
| Illinois City | $39,304 | $132,526 | $175,872 | $272,321 | $359,182 |
| Joy | $29,627 | $102,244 | $172,144 | $277,186 | $396,748 |
| Keithsburg | $14,808 | $63,296 | $116,378 | $194,779 | $278,554 |
| Lynn Center | $14,992 | $53,745 | $161,247 | $201,576 | $285,848 |
| Matherville | $38,913 | $58,561 | $114,052 | $213,310 | $246,236 |
| New Boston | $28,110 | $60,375 | $131,805 | $210,120 | $324,444 |
| New Windsor | $26,322 | $76,192 | $131,940 | $200,830 | $304,421 |
| North Henderson | $51,096 | $94,132 | $189,270 | $309,608 | $375,698 |
| Preemption | $51,585 | $74,250 | $103,635 | $218,168 | $261,441 |
| Reynolds | $35,390 | $123,165 | $194,708 | $292,736 | $380,651 |
| Seaton | $23,729 | $107,587 | $207,068 | $329,194 | $478,470 |
| Sherrard | $15,216 | $65,519 | $142,137 | $244,579 | $318,078 |
| Viola | $23,374 | $71,929 | $146,648 | $220,787 | $272,690 |
| Milan | N/A | N/A | N/A | N/A | N/A |
| Orion | N/A | N/A | N/A | N/A | N/A |
| Rio | N/A | N/A | N/A | N/A | N/A |
Source: Ownwell
Property Tax Bills Across Mercer County, Illinois
Property tax bills in Mercer County, Illinois are based on the assessed value of a home and the local tax rate applied to that value. For a home with a median market value of $150,030, the bill can vary widely depending on where the property is located and how it is assessed relative to nearby homes.
What homeowners pay is shaped by several factors, including the home’s assessed value, local taxing districts, and any exemptions that may reduce the final amount. In Mercer County, the 25th percentile tax bill is $2,247, while the 75th percentile is $6,848 and the 90th percentile reaches $10,539. That range shows how much property taxes can differ from one homeowner to another.
The highest median tax bill in the county is $6,641 in Seaton, while the lowest median tax bill is $2,566 in Matherville. For homeowners, this means property taxes can have a major impact on annual housing costs, especially when local assessments rise faster than expected.
Median Mercer County Tax Bill
$4,254
Median Illinois Tax Bill
$5,277
Median United States Tax Bill
$2,400
Property Tax Bills Across Mercer County, Illinois
| City | 10th Percentile | 25th Percentile | Median Tax Bill | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| Aledo | $1,224 | $2,298 | $4,260 | $7,402 | $11,304 |
| Alexis | $1,697 | $3,131 | $4,832 | $8,252 | $14,051 |
| Illinois City | $2,923 | $3,501 | $4,776 | $8,449 | $9,304 |
| Joy | $1,452 | $3,146 | $5,152 | $8,430 | $12,111 |
| Keithsburg | $540 | $1,647 | $3,434 | $5,546 | $8,934 |
| Lynn Center | $407 | $678 | $3,676 | $5,937 | $7,366 |
| Matherville | $1,075 | $1,490 | $2,566 | $5,281 | $6,547 |
| New Boston | $898 | $1,830 | $3,808 | $6,167 | $8,723 |
| New Windsor | $777 | $1,724 | $3,160 | $4,984 | $7,691 |
| North Henderson | $1,189 | $2,466 | $5,182 | $8,548 | $10,654 |
| Preemption | $1,416 | $1,947 | $3,001 | $5,786 | $6,488 |
| Reynolds | $2,143 | $3,694 | $5,582 | $9,116 | $12,781 |
| Seaton | $1,276 | $3,405 | $6,641 | $9,564 | $14,241 |
| Sherrard | $790 | $1,702 | $3,721 | $6,584 | $8,084 |
| Viola | $812 | $2,070 | $3,744 | $5,942 | $7,658 |
| Milan | N/A | N/A | N/A | N/A | N/A |
| Orion | N/A | N/A | N/A | N/A | N/A |
| Rio | N/A | N/A | N/A | N/A | N/A |
Source: Ownwell
Don't miss the deadline to appeal!
Dates | |
|---|---|
| Appeal Deadline | November 7 |
Links | |
|---|---|
| Mercer Tax Assessor | |
| Website | merceril.devnetwedge.com |