Property Tax Calculator
Look up a South Windsor property and see its real-estate tax bill at any mill rate, and what the same property has paid in past years.
- MILL RATE FY 2026-27
- ACS 2024 RELEASE
- PULLED 2026-08-10
- Mill rate — A mill is $1 of tax per $1,000 of assessed value. Connecticut assesses property at 70% of market value, so a posted rate is not comparable between towns.
- Medians, and why the town is left out of its own — A group is summarized by its median — the middle town, not the average. The subject town is excluded from its own group median, because a town cannot be part of the benchmark it is measured against.
- Revaluation — Every Connecticut town revalues its property on a five-year cycle. When values rise, the grand list grows and the posted mill rate steps down — even if the town collects exactly the same amount of tax.
- The grand list — The grand list is the assessed value of all taxable property in a town. It is dated October 1 and pays for the fiscal year starting the following July, so it always runs a year ahead of the budget it funds.
Full definitions, what each measure does not support, and the source behind it: How these numbers work.
Tax calculator
A yearly real-estate tax is assessment × mill rate ÷ 1,000. The numbers below start with this town’s median home and update as you type. Motor-vehicle and business-property taxes are billed separately and are not included.
Start typing a street address and choose a match — or skip this step and type an assessment in Step 2.
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From Step 1, your tax bill, or the town assessor. A Connecticut assessment is 70% of what the town judged the property was worth at its last revaluation.
The most recent adopted rate.
Starts at the current rate. Change it to see what any other rate would mean for this bill. The page proposes no rate of its own.
An estimate of the real-estate line of a tax bill, not a bill. Individual exemptions and credits (veterans, elderly and disabled homeowner programs and others) are not reflected, and some towns levy an additional district rate (fire or sewer) on part of the town that is not included here. The typed address and assessment stay in your browser; nothing is stored or sent anywhere.
About the assessment data (please read)
Address lookups use the State of Connecticut’s statewide parcel files, published on data.ct.gov. Between revaluations an assessment changes only through new construction, permits, demolition or an appeal, so for most properties the latest figure here is the one on the current bill. If a property changed recently, the town assessor’s own lookup is more current.
What would this home’s bill have been in each past year?
What this home’s bill would have been in past years
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Source: mill rates from CT OPM Mill Rates (emyx-j53e, field real_estate_personal), each matched to an assessment on its own grand_list_year. Recorded assessments from the state parcel files (i7xw-titi assessed_total; pqrn-qghw pre_yr_assessed_total and assessed_total; rny9-6ak2 assessed_total), joined parcel to parcel and dated against OPM’s class 100 grand list by Data/fetch_town_parcels.py into parcels.json. Earlier years are estimated with the revaluation factors in sales_history.json, measured by Data/fetch_ct_sales.py from CT OPM Real Estate Sales (5mzw-sjtu) and the Net Grand List by Town (webp-fgt3). Real estate only; exemptions, credits and district rates are not included.
How the estimate is built, and the independent ways each step was measured
Between revaluations a Connecticut assessment is frozen: it changes only through a permit, an appeal, a demolition or new construction. So one property’s assessment history is a step function with a step at each revaluation (CGS §12-62). Each step below was measured up to three ways from state data, depending on which sources reach that year. Where they disagree, the disagreement is the band on the chart.
And after adjusting for inflation?
The same bill in today’s dollars
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Source: the chart above, deflated with US CPI-U, All Urban Consumers, U.S. City Average, annual averages (BLS CUUR0000SA0, packaged as /data/us_cpi_u.json). A fiscal year carries the calendar year it begins in, the convention used across this site. CPI-U measures a household basket; indices built for what towns buy (wages, benefits, contracted services) have generally run above it.
How much did yearly bills change, home by home?
How much yearly bills changed, home by home
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Source: parcels.json (state parcel files i7xw-titi, pqrn-qghw, rny9-6ak2, via Data/fetch_town_parcels.py) and CT OPM Mill Rates (emyx-j53e, real_estate_personal). Each home’s bill in both years is its own recorded assessment × that year’s adopted mill rate ÷ 1,000. Homes are the parcels Data/cama_use.py classifies as single-family, condominium, two- to four-family, mobile home, or a dwelling filed without a type.
The data behind these charts
South Windsor’s own series behind the charts on this page, as text. Each table names the dataset it came from and the year of every row. The peer towns and group medians the charts also plot are not repeated here; they are in the same source files, linked in the footer.
Posted mill rate by fiscal year
| Fiscal year | Real estate and personal property | Motor vehicle | Grand list year |
|---|---|---|---|
| FY 2013-14 | 34.90 | 34.90 | 2012 |
| FY 2014-15 | 35.51 | 35.51 | 2013 |
| FY 2015-16 | 36.54 | 36.54 | 2014 |
| FY 2016-17 | 37.34 | 37.00 | 2015 |
| FY 2017-18 | 38.08 | 37.00 | 2016 |
| FY 2018-19 | 37.67 | 37.67 | 2017 |
| FY 2019-20 | 38.50 | 38.50 | 2018 |
| FY 2020-21 | 37.88 | 37.88 | 2019 |
| FY 2021-22 | 37.86 | 37.86 | 2020 |
| FY 2022-23 | 38.77 | 32.46 | 2021 |
| FY 2023-24 | 33.14 | 32.46 | 2022 |
| FY 2024-25 | 34.46 | 32.46 | 2023 |
| FY 2025-26 | 35.61 | 32.46 | 2024 |
| FY 2026-27 | 37.01 | 32.46 | 2025 |
A mill is $1 of tax per $1,000 of assessed value, and Connecticut assesses property at 70% of market value. A revaluation steps the posted rate down in that year even when the town collects the same amount of tax, so posted rates are not comparable across a revaluation or between towns. Source: CT OPM, Mill Rates (emyx-j53e).
Tax levy by property type, total tax levy and equalized mill rate by fiscal year
| Fiscal year | Real property levy | Personal property levy | Motor vehicle levy | Total tax levy | Equalized mill rate |
|---|---|---|---|---|---|
| FY 2018-19 | $83,943,366 | $11,281,533 | $8,327,414 | $103,552,313 | 26.42 |
| FY 2019-20 | $86,742,869 | $11,428,609 | $8,570,609 | $106,742,088 | 24.96 |
| FY 2020-21 | $87,230,632 | $11,699,682 | $8,796,693 | $107,727,007 | 24.06 |
| FY 2021-22 | $89,490,022 | $12,819,199 | $9,194,736 | $111,503,957 | 21.72 |
| FY 2022-23 | $92,517,068 | $13,200,078 | $9,739,918 | $115,457,065 | 20.76 |
| FY 2023-24 | $101,119,132 | $12,092,902 | $10,525,210 | $123,737,243 | 23.04 |
| FY 2024-25 | $106,067,064 | $13,215,641 | $10,174,603 | $129,457,308 | 19.98 |
| FY 2025-26 | $109,991,347 | $14,470,096 | $10,052,589 | $134,514,033 | 19.34 |
| FY 2026-27 | $114,878,433 | $15,938,759 | $10,478,505 | $141,295,697 | not reported |
The three property-type levies are what the town reported billing on land and buildings, on business equipment and other personal property, and on the vehicles on its October 1 list; they sum to the total. Supplemental motor-vehicle bills, for vehicles registered after October 1, are billed separately and are not in the total. Where a year's breakdown reads "Not reported", the state's row for that year was a partial filing or a zero and the total comes from the town's adopted budget instead, which has no breakdown. The equalized rate restates the levy against the market value of the town's property. That is what makes rates comparable between towns and across a revaluation; the posted rate above is not. Source: CT OPM, Tax Levy by Municipality and Special Tax District (he33-brru) and Equalized Net Grand List (8rr8-a322).
Net grand list by assessment class and grand list year
| Grand list year | Net grand list | Residential | Commercial | Motor vehicle | Personal property |
|---|---|---|---|---|---|
| 2011 | $2,771,257,781 | $1,884,523,439 | $517,933,641 | $204,559,970 | $165,395,960 |
| 2012 | not reported | $1,633,838,576 | $437,237,200 | $203,143,490 | $182,184,932 |
| 2013 | $2,505,704,902 | $1,640,728,440 | $439,529,851 | $210,557,305 | $215,111,466 |
| 2014 | $2,500,561,611 | $1,644,746,740 | $451,712,231 | $210,321,900 | $195,128,330 |
| 2015 | $2,544,025,485 | $1,652,897,404 | $468,571,691 | $210,690,850 | $203,057,960 |
| 2016 | $2,601,659,925 | $1,676,890,424 | $466,967,840 | $217,152,451 | $241,078,150 |
| 2017 | $2,743,418,239 | $1,724,793,303 | $488,716,628 | $221,062,220 | $297,459,302 |
| 2018 | $2,768,191,892 | $1,745,085,412 | $503,864,078 | $225,192,240 | $296,363,076 |
| 2019 | $2,853,659,284 | $1,769,118,352 | $548,984,417 | $235,040,935 | $309,573,624 |
| 2020 | $2,956,938,318 | $1,782,465,985 | $596,344,187 | $245,755,512 | $341,067,298 |
| 2021 | $3,043,924,618 | $1,793,421,931 | $627,423,117 | $303,759,845 | $343,761,969 |
| 2022 | $3,758,656,659 | $2,383,589,020 | $680,633,250 | $326,897,967 | $365,315,680 |
| 2023 | $3,785,653,629 | $2,395,946,920 | $685,518,950 | $316,103,335 | $383,106,424 |
| 2024 | $3,820,053,295 | $2,414,098,610 | $688,796,750 | $312,424,210 | $406,351,555 |
| 2025 | $3,871,775,105 | $2,433,029,110 | $684,575,610 | $325,280,280 | $430,805,265 |
Assessed values, at 70% of market value. The grand list year runs ahead of the fiscal year that taxes it, so a grand list year and a fiscal year on this page are not the same period. Source: CT OPM, Net Grand List by Town (webp-fgt3).
Income and housing by survey release
| ACS release | Median household income | Per-capita income | Median home value | Median gross rent | Population |
|---|---|---|---|---|---|
| 2009 | $88,643 | $38,659 | $266,600 | $1,029 ±161 | 25,915 |
| 2010 | $88,350 | $38,945 | $276,100 | $1,030 ±137 | 25,476 |
| 2011 | $92,513 | $39,248 | $274,600 | $1,050 ±87 | 25,577 |
| 2012 | $91,519 | $40,318 | $276,300 | $1,112 ±88 | 25,684 |
| 2013 | $90,499 | $41,398 | $271,700 | $1,124 ±51 | 25,756 |
| 2014 | $94,217 | $44,569 | $272,100 | $1,177 ±72 | 25,795 |
| 2015 | $97,389 | $45,100 | $276,300 | $1,133 ±56 | 25,806 |
| 2016 | $100,122 | $46,758 | $276,200 | $1,152 ±75 | 25,793 |
| 2017 | $105,986 | $46,900 | $281,100 | $1,128 ±78 | 25,802 |
| 2018 | $107,088 | $47,189 | $282,200 | $1,317 ±163 | 25,823 |
| 2019 | $107,374 | $47,910 | $287,100 | $1,290 ±278 | 25,898 |
| 2020 | $119,972 | $53,513 | $290,500 | $1,510 ±230 | 25,962 |
| 2021 | $126,996 | $56,976 | $291,400 | $1,595 ±104 | 26,719 |
| 2022 | $134,080 | $60,781 | $324,200 | $1,602 ±144 | 26,805 |
| 2023 | $143,025 | $63,825 | $354,500 | $1,679 ±236 | 26,820 |
| 2024 | $144,961 | $66,277 | $375,100 | $1,864 ±214 | 26,907 |
Each release is a rolling five-year average, not a single year, so consecutive releases overlap and should not be read as year-over-year change. Median home value is what owners report to the survey, not an assessment. Gross rent is contract rent plus the estimated cost of utilities and fuels where the renter pays them, so it is not the figure on a lease; it covers renter-occupied units, while median home value covers owner-occupied ones. The number after ± is the 90% margin of error the Census publishes with that estimate. Source: US Census Bureau, American Community Survey 5-year estimates. Median gross rent is ACS 5-year, B25064.