Wisconsin Equalization Process

Wisconsin has a two-tiered process: local assessments, and state equalization. The process of establishing full values for municipalities is referred to as "Equalization".

Because local assessors may value property at different percentages of market value, the rule of uniformity would be violated if the assessed values were used to apportion levies for taxing authorities with property in more than one town, city, or village. Equalized values provide a more equitable distribution for apportioned tax levies, based upon the proportion of full property value each one bears in relation to the taxing jurisdiction's full value.



County Tax To Collect






City A

Village B

Town C







Municipality Assessed Value





Apportioned Rate (Assessed)

($30,000 divided by $30,000,000)


Municipal CountyApportionment










Level of Assessment





Equalized/Full Value





Apportioned Rate (Equalized)

($30,000 divided by $44,285,700)


Municipal CountyApportionment






To determine full values for municipalities, the Wisconsin Department of Revenue uses assessment/sales ratio analysis. This develops the relationship between assessed values and actual sales prices. Dividing the total assessed value of the sales in the municipality each year, by the total sale price calculates an annual equalization ratio. If the ratio is 95%, the state increases the municipality's assessed value by 5% to determine the full value of the municipality. If that ratio is 105%, the state decreases the municipality's assessed value by 5% to determine the full value of the municipality.

A sample of the method for establishing full values is shown below.



Assessed Value of Properties Sold


Sale Price Total of Properties Sold


Ratio Calculation ($28,300,000 divided by $28,100,000)


Level of Assessment (State Economic Adjustment)



Previous Years Assessed Value



Value Added From Annexations


Value Added From New Construction


Value Added From Exempt Property Turning Assessable


Value Added From Assessment Reviews


Value Loss From Razed or Depreciated Buildings


Value Loss From Property Now Exempt


Value Loss From Reviews


Value Difference



Adjusted Assessed Value ($650,000,000 + $21,250,000)



Assessed Value Economically Adjusted ($671,250,000 / 100.71%)


Full Value Manufacturing Values (By Department of Revenue)


Equalized Value of Municipality ($666,517,724 + $42,000,000)



Manufacturing Assessed Value ($42,000,000 X 100.71)


Final Assessed Value for Municipality ($671,250,000 + $42,298,932)


Because Wisconsin has the two-tiered valuation process, both values are printed on the tax bills, along with the level of assessment. As shown in the chart above, the level of assessment is determined by dividing the total assessed value of properties that have sold by the total sale price. On the tax bills, the equalized value is shown as "total estimate of fair market value", and is calculated by dividing the individual parcel's assessed value by the level of assessment. 

When the level of assessment is 100%, the assessed value is the same as the estimate of fair market value.

When the level of assessment is over 100%, the estimate of fair market value is less than the assessed value.

When the level of assessment is less than 100%, the estimate of fair market value is higher than the assessed value.

The "estimate of fair market value" is printed on the tax bills only to give taxpayers an idea of the market value of the property. It should be kept in mind that the ratioed value on the tax bill is not developed from the analysis or stratification of sales of similar properties. Owners should request a market value estimate from an appraiser or realtor before selling any property on the open market for the "estimated fair market value" printed on the tax bill.

The economic adjustments applied to towns, cities and villages by the state develop an indicator of the entire municipality's full value. However, when used in reverse on individual properties, the process strictly develops equalized values - not market values - as shown below.


Sale #


Sale Price Or Market Value

Tax Bill "Estimated Market Value"

Tax Bill "Estimated Market Value" Calculation





($ 98,000 div by .8702)





($ 35,000 div by .8702)





($ 60,000 div by .8702)





($ 218,500 div by .8702)





($ 18,000 div by .8702)





($ 547,000 div by .8702)





($ 125,000 div by .8702)





($ 135,000 div by .8702)






Aggregate Ratio:

$1,236,500 divided by $1,421,000