How to Calculate Tax Deductions for Wisconsin

by Pedro Carrasquillo ; Updated July 27, 2017
A taxpayer prepares his income tax return.

Calculating your Wisconsin tax deductions is not a complicated procedure. Under Wisconsin personal income tax law, taxpayers are eligible to claim both a standardized and itemized deduction on their state income tax return. The standardized deduction is available to all Wisconsin filers who meet the income filing requirements. The itemized deduction allows you to claim a credit for certain federal government deductions you can claim on schedule A of the federal income tax return.

Step 1

Calculate your Wisconsin income tax as required by law on Form 1, lines 1 through 13. Add your federal adjusted gross income, to your state and municipal interest payments received, and capital gains received and then subtract from this sum total any state tax refund you received, any United States government interest, unemployment compensation, or Social Security adjustment payments you received. The net total of this calculation can be found on line 14 of your Form 1 tax return. A copy of the Wisconsin Form 1 income tax return form can be obtained online at the Wisconsin Department of Revenue website.

Step 2

Establish your standard deduction. For example, if you are single and earned $80,000 in 2010 your standard deduction would be $1,339. This information can be viewed on the income tax standard deductions table contained in the Wisconsin tax Form 1 instruction booklet, a copy of which may be viewed online at the Wisconsin Department of Revenue website.

Step 3

Itemize your deductions on Schedule 1 of Wisconsin tax Form 1. This includes adding up all deductions you can claim from the federal government schedule A tax form, including medical and dental expenses, interest paid, gifts to charity, and casualty losses. The sum total of these deductions is your total itemized deduction amount.

Step 4

Subtract your standardized deduction from your total itemized deduction amount. For example, if you are a single filer and you earned $80,000 in 2010 and had $4,300 in total itemized deductions and $1,339 in standardized deduction you would subtract $1,339 from $4,300 to arrive at $2,961.

Step 5

Multiply the difference between your total itemized deductions and standardized deduction by 5 percent to calculate your Wisconsin itemized deduction credit. For instance, if the difference between your total itemized deductions and standardized deduction is $2,961, multiply this amount by 5 percent to arrive at your itemized deduction credit amount of $148.05.

About the Author

Pedro Carrasquillo began writing professionally in 2002 while working for the New Jersey state legislature. He coauthored the legislature's annual "Budget Analysis for the Department of Community Affairs" from 2002-07. Carrasquillo holds a Bachelor of Arts in comparative literature from Haverford College as well as a Master of Science in public policy and management from Carnegie Mellon University.

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