Wisconsin child support calculator: how the numbers actually work

Last updated 2026-07-09

What formula does Wisconsin use to calculate child support?

Wisconsin uses the percentage-of-income standard, which is simpler than the income-shares model most states use. You take the payer's monthly gross income and multiply it by a set percentage based on how many children are covered. That's the baseline number.

The percentages come from Wisconsin Administrative Code DCF 150, the official rule that governs child support in the state ^[1]. They are:

Number of children	Percentage of gross income
1	17%
2	25%
3	29%
4	31%
5 or more	34%

Earn $5,000 per month gross with two kids, and the baseline number is $1,250 per month. That's the whole standard calculation. The receiving parent's income doesn't factor in under the basic formula, which is a meaningful difference from states like South Carolina (more on that below).

This percentage-of-income approach has been Wisconsin's standard since 1987, one of the longest-running formulas in the country ^[1]. The trade-off is speed. The math is fast and predictable, but it can feel blunt in high-income or shared-placement situations.

How do you find gross income for the Wisconsin child support calculation?

Gross income means income before taxes and most deductions. Wisconsin's DCF 150 defines it to include wages, salaries, tips, self-employment income (after business expenses), bonuses, commissions, rental income, investment income, unemployment compensation, Social Security benefits, and workers' compensation payments ^[1].

What's excluded? Means-tested public assistance like FoodShare and SSI, foster care maintenance payments, and child support you're already paying for children from a prior order.

Self-employment income is where people get confused. You subtract legitimate business expenses to arrive at net self-employment profit, and that profit is what counts as gross income for support purposes. The IRS Schedule C is the usual starting point, but the court can adjust if it thinks expenses are inflated.

If a parent is voluntarily unemployed or underemployed, Wisconsin courts can impute income, meaning they assign a fictional income based on what the person could earn. The benchmark is usually prior earnings history or what someone with similar education and work history earns in the local market ^[1]. Don't try to game this by quitting a job before a support hearing. Judges see it constantly.

For W-2 employees, box 1 of your W-2 is wages paid, but add back pre-tax 401(k) contributions and health insurance premiums. Those reduce box 1, yet Wisconsin counts them as gross income for support.

How does shared placement change the Wisconsin child support calculation?

When both parents have the child at least 25% of overnights per year (92 or more nights), Wisconsin switches from the straight percentage formula to a shared-placement formula ^[1]. This matters a lot because it usually lowers the payment.

The shared-placement formula works like this:

1. Calculate each parent's base obligation using the standard percentages as if they were the payer. 2. Multiply each obligation by 1.5 (the shared-placement multiplier). 3. Multiply each adjusted obligation by the percentage of time the child spends with the other parent. 4. Subtract the smaller result from the larger. The parent with the larger number pays the difference.

In plain terms: if you have the child 40% of nights and your co-parent has the child 60% of nights, you're both spending money on the child during your respective time. The formula tries to account for that.

The 25% threshold (92 overnights) is a hard line. If one parent has 91 overnights, the standard formula applies. That single night can mean hundreds of dollars per month in some cases, so parenting plan negotiations often circle back to this number.

Wisconsin's court system provides a shared-placement worksheet as part of its official self-help resources at wicourts.gov ^[2]. Use that worksheet rather than building your own spreadsheet. The 1.5 multiplier and the order of the steps are easy to get wrong.

Where is the official Wisconsin child support calculator online?

The Wisconsin Department of Children and Families (DCF) and the Wisconsin Court System both publish resources for calculating support. The most direct route is the Wisconsin Court System's self-help center at wicourts.gov, which links to the official worksheets ^[2].

The Wisconsin DCF also runs a child support program page that explains the formula and points parents to the administrative system ^[3].

There's no public interactive calculator on the Wisconsin Circuit Court Access (WCCA) system where you type in your numbers, but several county child support agencies provide fill-in worksheets. Portage County, Dane County, and Milwaukee County each publish their own PDF worksheets that walk through the DCF 150 math step by step. These aren't unofficial guesses. They're the same formula, just formatted differently.

Want to cross-check your number fast? The standard formula is genuinely simple: gross monthly income times the applicable percentage. You can do it on a napkin. The calculator tools earn their keep in shared-placement scenarios and deviation requests, where the inputs multiply fast.

A word on third-party calculators you'll find through a web search. Many are accurate enough for a ballpark, but some haven't been updated to current DCF 150 rates, and others fumble shared placement. Verify your result against the official percentages in Wis. Admin. Code DCF 150.03 ^[1].

What is the income cap for Wisconsin child support, and what happens above it?

Wisconsin caps the income subject to the standard percentage formula. Under DCF 150, the reference cap sits at gross income of $7,000 per month for the payer ^[1]. Above that level, the court doesn't automatically apply the percentage to every additional dollar.

Above the cap, the standard practice is for the court to set an amount based on the needs of the children and the lifestyle they would have had if the family had stayed together. That's a much more fact-intensive inquiry, and the court has discretion to order more than the capped percentage would produce.

High-income support orders in Wisconsin start to look like the income-shares analysis other states use. What does the child actually need, what standard of living were they accustomed to, and how do both parents' resources match that need?

For most people reading this, the cap isn't relevant. Median household income in Wisconsin was about $72,800 in 2023 according to the U.S. Census Bureau ^[4], which works out to roughly $6,067 per month gross, just below the cap. If you or your co-parent earns well above average, talk to a divorce attorney before relying on the standard percentages.

What deviation factors can change the Wisconsin support amount?

The percentage formula gives you a presumptive number. Courts can order more or less than that number if a party shows that applying the standard amount would be unfair. Wisconsin's deviation factors under DCF 150.04 include ^[1]:

• The financial resources of both parents, including assets and debts
• The needs of each child, including physical, emotional, and educational needs
• The child's standard of living if the family had stayed together
• Tax consequences to each parent
• The contributions of each parent toward the child's health insurance
• The cost of child care related to employment or job training
• Whether a parent is also supporting other children from a different household
• Extraordinarily high or low income that makes the percentage result unreasonable
• Any other relevant factors the court determines in the interest of justice

Deviation isn't automatic, and it isn't common. Courts start with the percentage and need a specific, documented reason to move away from it. Saying the number feels high does nothing. You need actual figures: here's what health insurance costs, here's the child care bill, here's why the standard formula produces an absurd result given these facts.

The burden falls on the parent requesting deviation. Trying to get a lower order based on high debt? Bring documentation. Pay stubs, tax returns, and bills move courts. Arguments don't.

How does Wisconsin's formula compare to South Carolina's child support calculator?

This question comes up constantly in forums where people compare their situation to a friend or family member in another state. The difference is real.

Wisconsin uses the percentage-of-income model, where only the paying parent's income drives the number. South Carolina uses the income-shares model, where both parents' incomes are combined to estimate what the child would have received if the parents were together, and then each parent's share of that combined income sets their share of the obligation ^[5].

The South Carolina Department of Social Services publishes its own guidelines and worksheet ^[8], and South Carolina's child support calculator follows the income-shares table set in S.C. Code Ann. Section 63-17-470 ^[5].

Here's the contrast:

Feature	Wisconsin	South Carolina
Model	Percentage-of-income	Income-shares
Whose income counts?	Payer only (standard formula)	Both parents
Basic rate (1 child)	17% of payer's gross	Determined by combined income table
Shared placement adjustment	Yes, at 92+ overnights	Yes, at 109+ overnights (roughly 30%)
Self-support reserve	No explicit reserve	Yes, low-income adjustment

Neither model is universally more generous or more burdensome. A low-earning payer with a high-earning recipient ends up with very different results depending on which state's formula applies. The income-shares model often produces lower orders when the paying parent earns much less than the receiving parent, because the receiving parent's income is factored in. Wisconsin's standard formula ignores that entirely.

How is child support handled in an uncontested Wisconsin divorce?

If you and your spouse agree on the support amount, you write that agreement into your Marital Settlement Agreement. The court still reviews it to confirm it's in the children's best interest and that it conforms to DCF 150, or that any deviation is explained ^[6].

The standard approach in an uncontested case: run the formula, present the number, both parties sign off. Courts rarely reject agreed-upon numbers that match the formula. Things get scrutinized when an agreed amount lands well below the formula result, which triggers the court's duty to ask whether the deviation is genuinely in the child's interest.

You'll attach a Child Support Worksheet to your divorce paperwork. Wisconsin's official court forms include the Findings of Fact, Conclusions of Law, Judgment of Divorce, and a separate Child Support Addendum ^[2]. The worksheet shows the court how you reached the number.

For parents doing their own paperwork, divorce papers packages that include child support worksheets save real time. DivorceClear's $149 document packet covers Wisconsin uncontested divorce and includes the child support calculation worksheet along with the other required forms, which is worth knowing if you're trying to do this without paying attorney's fees.

Filing fees in Wisconsin vary by county. Dane County charges $184.50 for a divorce filing as of 2024 ^[7]. Milwaukee County is similar at roughly $184.50 ^[7]. These fees are separate from any document preparation costs.

Can child support in Wisconsin be modified after the divorce?

Yes, and this is one of the most practical things to understand before you finalize a number. Wisconsin allows modification when there has been a substantial change in circumstances since the last order ^[6].

What counts as substantial? A change in a parent's income of 15% or more (up or down) is the clearest example. A change in the child's needs, a change in placement time, or the payer becoming unemployed can also qualify. Wisconsin statute 767.59 governs post-judgment modifications ^[6].

The 15% threshold gives you a benchmark. Got a raise last year that pushed your income up 10%? That alone won't win a modification motion. At 15% or more, the door is open.

Modification requests go back to the circuit court. You file a motion, provide updated financial information, and the court recalculates using the current formula. If the new number differs from the existing order by 15% or more, the court will likely modify. Below 15%, the court has discretion but usually won't.

Administrative review is also available through the county child support agency. Every three years, either parent can request an administrative review of the support amount without hiring a lawyer or filing a court motion. The agency recalculates based on updated income information and recommends a new amount, which the court can then adopt ^[3].

A lot of parents don't know about this three-year cycle. If your income dropped two years ago and you never filed anything, you may have been paying more than the current formula would require.

What happens if a parent doesn't pay Wisconsin child support?

Wisconsin child support is enforced through the state's child support program, administered at the county level under the Wisconsin DCF ^[3]. The enforcement tools are substantial.

The first and most common tool is income withholding. Under Wisconsin law, income withholding is automatic in almost every support order ^[6]. The payer's employer gets a withholding notice and deducts the support directly from each paycheck. This happens without any extra action by the receiving parent.

If income withholding doesn't collect the full amount (because the payer is self-employed, say), the agency can pursue license suspension. Wisconsin can suspend a driver's license, professional license, recreational license, and even a passport application for unpaid support ^[3].

Unpaid support piles up as arrears and carries interest. Wisconsin charges interest on arrears at 1% per month (12% per year) under Wis. Stat. 767.89 ^[6]. Arrears also surface on credit reports and can trigger tax refund intercepts at both the state and federal level.

Criminal prosecution is reserved for serious cases, but it's real. Felony nonsupport under Wis. Stat. 948.22 applies when a person intentionally fails to pay support they can afford ^[6]. Most people in arrears reach payment plans long before that point. The statute exists, and it gets used.

What do parents often get wrong when estimating Wisconsin child support?

A handful of mistakes come up over and over when parents calculate their own number.

Using net instead of gross income is the most common. The formula runs on gross, so plugging in your take-home pay produces a number that's too low, sometimes by 20-30% depending on your tax situation. Always start with gross.

Ignoring overtime or bonuses is another. Courts look at total gross income, including regular overtime and recurring bonuses. If you've worked 10 hours of overtime every week for three years, a court is likely to count that as part of your base income, not a windfall.

Miscounting placement overnights is surprisingly frequent. The gap between 91 and 92 overnights decides whether you use the standard or shared-placement formula. Count the actual nights, not rough percentages, before running any numbers.

Assuming health insurance is automatically subtracted. Wisconsin's formula doesn't subtract health insurance premiums before calculating the percentage. Health insurance is handled separately, usually as a deviation factor or a separate cost-sharing order alongside the base support.

For anyone in an uncontested divorce who wants the wider view of what the process costs, understanding the full range of divorce-related costs helps set realistic expectations before you finalize any agreement.

One thing that's genuinely hard to pin down is how often deviation requests succeed. Wisconsin's court system doesn't publish statistics on deviation rates, and the closest proxy is anecdotal from family law practitioners. The general sense is that courts grant deviation in maybe 10-15% of contested support hearings, but nobody has clean public data on that number.

How does child support interact with custody and placement in Wisconsin?

Legal custody (who makes decisions) and physical placement (where the child lives) are separate from child support, but they're connected in practice.

In Wisconsin, physical placement time directly affects the support calculation once you hit the 92-overnight threshold. This creates a financial incentive in placement negotiations that parents and courts both recognize. A parent who secures 92+ overnights per year lowers their support exposure under the shared-placement formula. Courts watch for this and look for parenting plans that actually serve the child, not plans engineered around a financial cutoff.

Legal custody has almost no direct effect on the support number. Sole legal custody versus joint legal custody doesn't change the formula. What matters is where the child sleeps.

Child support orders are separate from placement orders in Wisconsin, but both usually appear in the same judgment of divorce. You can't withhold placement because support isn't being paid, and you can't withhold support because placement is being denied. These are separate legal obligations. Self-help remedies (refusing to bring the kids, stopping payments) create legal problems for the parent who tries them.

Parents working through the full picture of custody arrangements should understand how children and custody issues affect the whole divorce before signing any agreement. It's time well spent.

Frequently asked questions

What percentage of income is child support in Wisconsin for one child?

Wisconsin requires the paying parent to pay 17% of their gross monthly income for one child. This comes directly from Wisconsin Administrative Code DCF 150.03. So a parent earning $4,000 per month gross pays $680 per month. The receiving parent's income is not part of the standard calculation. The percentage rises with more children: 25% for two, 29% for three.

Does Wisconsin use a child support calculator for shared placement?

Yes, but it's a different formula. When each parent has at least 92 overnights per year (25%), Wisconsin applies a shared-placement calculation that multiplies each parent's base obligation by 1.5, then adjusts by the percentage of time the child spends with the other parent. The Wisconsin Court System publishes an official shared-placement worksheet at wicourts.gov. The standard percentage formula does not apply in shared-placement cases.

How do I use the official Wisconsin child support calculator?

The Wisconsin Court System at wicourts.gov provides child support worksheets as part of its self-help forms. For the standard formula, multiply your gross monthly income by the applicable percentage (17% for one child, 25% for two, and so on). For shared placement, use the official worksheet because the 1.5 multiplier and sequential steps are easy to miscalculate. The Wisconsin DCF child support program page also provides guidance and local county agency contacts.

What counts as income for Wisconsin child support purposes?

Wisconsin includes wages, salaries, tips, bonuses, commissions, self-employment profit (after legitimate business expenses), rental income, investment income, unemployment compensation, Social Security benefits, and workers' compensation. Means-tested public assistance like SSI and FoodShare is excluded. Pre-tax deductions like 401(k) contributions are added back because the formula uses gross income before those deductions.

Can Wisconsin child support be lower than the guideline amount?

Yes, if a party proves the standard amount would be unfair. DCF 150.04 lists deviation factors including each parent's financial resources, the child's specific needs, health insurance costs, child care expenses, and support obligations for other children. Deviation requests require documentation and a specific reason. Courts start with the formula number and need a concrete, documented reason to move away from it. Bare assertions rarely succeed.

How often can Wisconsin child support be modified?

Either parent can request an administrative review of the support amount every three years through the county child support agency. A court modification can be requested any time there's a substantial change in circumstances, typically a 15% or greater change in either parent's income. Wisconsin statute 767.59 governs modifications. The court recalculates using the current formula and updates the order if the new amount differs from the current order by 15% or more.

Does Wisconsin child support automatically end when a child turns 18?

Generally yes, with exceptions. Support continues until age 18, or until age 19 if the child is still enrolled full-time in high school and can reasonably be expected to graduate before age 19. Courts can also order post-secondary education support (college contributions), but that's a separate order, not an automatic extension of the child support order. Wisconsin statute 767.511 covers duration and education support provisions.

What is the income cap for Wisconsin child support?

Wisconsin's standard percentage formula applies up to $7,000 per month in gross income under DCF 150. Above that cap, the court has discretion to set a higher amount based on the child's needs and the standard of living the child would have had if the family stayed together. The formula percentages don't automatically apply dollar-for-dollar on every dollar above $7,000. High-income cases are much more fact-specific.

How is Wisconsin child support different from South Carolina's calculation?

Wisconsin uses the percentage-of-income model, where only the paying parent's income determines support. South Carolina uses the income-shares model under S.C. Code Ann. Section 63-17-470, where both parents' incomes are combined to estimate total child-rearing costs, then split proportionally. South Carolina's approach can produce lower payments when the payer earns significantly less than the recipient, because the recipient's income offsets part of the total. Wisconsin's standard formula ignores the receiving parent's income entirely.

What happens to child support in Wisconsin if the paying parent loses their job?

The existing order stays in place until a court modifies it. Losing a job is a substantial change in circumstances that justifies filing a modification motion under Wis. Stat. 767.59. Until the court modifies the order, arrears accumulate on the old amount. File the modification motion quickly because courts typically won't backdate a reduction to before the filing date. Contact the county child support agency; some have expedited processes for income-loss situations.

Does Wisconsin child support cover health insurance and child care costs separately?

The base percentage formula covers basic support only. Health insurance and child care are handled as separate add-ons. Courts typically order one or both parents to maintain health insurance for the child and may divide uninsured medical costs proportionally. Child care costs related to a parent's employment or job training are often ordered as a separate monthly contribution. These extras appear in the same divorce judgment but are calculated separately from the base support number.

How does Wisconsin enforce unpaid child support?

Income withholding is automatic in virtually every Wisconsin support order, deducting payments directly from the payer's paycheck. Additional tools include driver's license and professional license suspension, passport denial, tax refund intercepts at the state and federal level, credit reporting, and bank account liens. Arrears carry 1% monthly interest (12% annually) under Wis. Stat. 767.89. Intentional nonpayment can result in felony charges under Wis. Stat. 948.22 in serious cases.

Do parents have to use the Wisconsin formula in an uncontested divorce, or can they agree to a different amount?

Parents can agree to a different amount, but the court will review it. If the agreed amount is below the formula number, the court will ask why and whether the deviation serves the child's best interest. Courts typically accept agreed amounts that match or exceed the formula without question. If you deviate below the guideline, document your reasons in the settlement agreement. The formula creates a presumption, not an absolute floor, but going below it takes explanation.

Sources

1. Wisconsin Legislative Documents, Wis. Admin. Code DCF 150 (Child Support Percentage of Income Standard): Wisconsin child support percentages: 17% for one child, 25% for two, 29% for three, 31% for four, 34% for five or more; deviation factors; gross income definition; $7,000/month cap; shared placement threshold of 25% overnights (92 nights)
2. Wisconsin Court System, Self-Help Center and Family Law Forms: Official child support worksheets, shared-placement worksheet, and divorce forms including child support addendum are published by the Wisconsin Court System
3. Wisconsin Department of Children and Families, Child Support Program: Wisconsin DCF administers the child support program at the county level; three-year administrative review process; enforcement tools including license suspension
4. U.S. Census Bureau, American Community Survey, Wisconsin Median Household Income 2023: Median household income in Wisconsin was approximately $72,800 in 2023
5. South Carolina Legislature, S.C. Code Ann. Section 63-17-470, Child Support Guidelines: South Carolina uses the income-shares model for child support, combining both parents' incomes to determine total child-rearing costs
6. Wisconsin Legislature, Wis. Stat. Chapter 767, Actions Affecting the Family: Wis. Stat. 767.59 governs modifications (substantial change, 15% threshold); 767.511 covers child support duration; 767.89 sets 1% monthly interest on arrears; 948.22 covers felony nonsupport; income withholding is automatic in support orders
7. Wisconsin Circuit Court, Filing Fee Schedules, Dane County and Milwaukee County: Divorce filing fees in Wisconsin are approximately $184.50 in Dane County and Milwaukee County as of 2024
8. South Carolina Department of Social Services, Child Support Services: South Carolina DSS administers child support guidelines and publishes the income-shares worksheet used in SC child support calculations
9. U.S. Department of Health and Human Services, Office of Child Support Services: Federal overview of state child support models including percentage-of-income and income-shares approaches used across states