Wisconsin Child Support Calculator

Wisconsin calculates child support using the Percentage of Income Standard, established under Wis. Admin. Code § DCF 150. Unlike the Income Shares model used by most states, Wisconsin's approach focuses almost entirely on the paying parent's gross monthly income rather than combining both parents' incomes. The applicable percentage is determined by the number of children subject to the support order: 17% of gross income for one child, 25% for two children, 29% for three children, 31% for four children, and 34% for five or more children. These percentages are set in statute and apply uniformly across the state, making Wisconsin's child support calculation among the most straightforward and transparent in the country.

The percentage standard is designed to approximate the proportion of a parent's income that would have been spent on the child had the family remained together. Wisconsin's approach reflects a policy choice to simplify administration and increase predictability — both parents can calculate the expected support amount from publicly available tables without needing to gather the other parent's financial information. This transparency reduces disputes over income disclosure in many cases, though disagreements about what constitutes gross income remain a common source of litigation in Wisconsin family courts.

Wisconsin's guidelines also specify how support is calculated when the paying parent has income from multiple sources or when their income fluctuates significantly. For parents with variable income — such as seasonal workers or commission-based employees — courts may calculate an average monthly gross income based on a full year of earnings rather than using any single month's pay. This averaging approach produces a more stable support obligation that better reflects the parent's annual earning capacity rather than creating an obligation that swings dramatically from month to month based on income volatility.

Wisconsin defines gross income for child support purposes to include wages, salaries, commissions, bonuses, overtime, tips, and net self-employment income. Investment income including dividends, interest, capital gains, and rental income is also included. Social Security benefits including disability payments, pension and retirement distributions, unemployment compensation, and workers' compensation are counted. The comprehensive definition ensures that parents cannot reduce their apparent income by routing funds through investment accounts, business structures, or irregular income streams that would not appear on a standard pay stub.

Self-employed parents in Wisconsin face close scrutiny of their reported gross income. Courts look at business gross receipts and subtract legitimate business expenses to arrive at net self-employment income, which then enters the percentage calculation. However, non-cash deductions such as depreciation and amortization that reduce taxable income without reducing actual cash flow may be added back for child support purposes. Business expenses that serve both personal and business purposes — vehicle use, meals, cell phones — are scrutinized to ensure only the genuinely business portion is deducted. Courts frequently require several years of tax returns and profit-and-loss statements to evaluate self-employment income accurately.

When a parent is voluntarily unemployed or underemployed without a valid reason, Wisconsin courts may impute income to that parent at the level they could reasonably earn. Courts consider the parent's education, training, work history, and the prevailing wages available for their occupation in the local labor market. A parent who voluntarily leaves a high-paying job, reduces hours without legitimate reason, or refuses available employment opportunities may have income imputed to them at their prior earnings level or at the prevailing wage for their occupation. Imputation protects children from a parent deliberately reducing their income to lower their support obligation.

Wisconsin has specific provisions addressing situations where a paying parent is supporting children from multiple relationships. When a parent already has a prior child support order for children from another relationship, Wisconsin allows an adjustment to the gross income used for the subsequent order. The adjustment prevents a parent from being required to pay percentages of gross income that, in combination, would exceed what the percentages were designed to represent for the total number of children. Without this adjustment, a parent could be required to pay 17% for a first child from one relationship and then 25% for two children from a second relationship, resulting in 42% total for three children when the three-child percentage is only 29%.

The serial family adjustment works by converting prior support orders into an equivalent percentage of the parent's gross income and then reducing the gross income available for the subsequent order calculation. Wisconsin courts apply a specific formula to ensure fairness across multiple families while preventing any individual child from receiving disproportionately more or less than their fair share of the parent's financial resources. This calculation can become complex when a parent has obligations to children from three or more relationships, and courts often benefit from detailed financial worksheets prepared by the parties' attorneys.

Wisconsin also recognizes that a parent's obligation to biological or adoptive children living in their own household is a relevant consideration when evaluating deviations from the standard percentage. When a paying parent is supporting children living with them full time, courts have discretion to consider those direct expenses in determining whether the standard percentage produces an equitable result. While these in-home children do not automatically reduce the support obligation the way a prior court order does, they are a recognized factor in the deviation analysis and may support a below-guideline order when the paying parent's total household costs are documented and substantial.

Wisconsin has a specific shared-placement formula that applies when both parents share physical placement of the child for a significant portion of the year. For shared placement to trigger the alternative formula, each parent must have the child for at least 25% of the annual placement time — approximately 92 nights per year. When this threshold is met, the standard percentage of income calculation is replaced with a formula that accounts for both parents' incomes and each parent's placement share, producing a lower net transfer payment to reflect the fact that both parents are directly funding the child's housing, food, and daily expenses during their respective placement periods.

The Wisconsin shared-placement formula requires both parents' monthly gross incomes. Each parent's payment is calculated as if they were the paying parent using the standard percentage, and then each result is multiplied by the other parent's placement percentage. The net transfer payment is the difference between the two calculated amounts, with the higher-income parent paying the lower-income parent. This cross-credit approach ensures that both parents' financial resources and actual placement time contribute to the result, rather than the standard formula's focus on only the paying parent's income and the full guideline percentage.

Courts evaluate the actual placement schedule, not the formal custody designation, when applying the shared-placement formula. A parent who has joint legal custody but who actually has the child for fewer than 25% of overnights will not qualify for the shared-placement calculation. Conversely, a parent with sole legal custody who voluntarily allows the other parent to have the child for more than 25% of the year may find that the other parent successfully argues for the shared-placement formula. Documentation of actual placement time is important, particularly when disputes arise about whether the threshold has been met.

Wisconsin courts may deviate from the standard percentage when application of the guideline would be unfair to the child or to either party. Statutory deviation factors include the financial resources of each parent, the child's educational, physical, and emotional needs, the standard of living the child would have had if the family remained intact, the desirability of the custodial parent remaining at home as a full-time caregiver, and the child's extraordinary medical or educational costs. Courts may deviate upward or downward from the percentage, but any deviation must be supported by specific written findings.

Deviation is more commonly sought when the paying parent has an extremely high income and the standard percentage would produce an amount far exceeding the child's actual needs, or when the paying parent's income is so low that the standard percentage would leave them unable to meet their own subsistence requirements. Wisconsin courts generally apply a minimum support order — often $25 per month — for parents at the very lowest income levels, ensuring that even parents with minimal resources make some financial contribution to their child while retaining enough income to survive. As income increases, the standard percentage applies without adjustment unless specific deviation factors are demonstrated.

Wisconsin child support orders may be modified when there has been a substantial change in the financial circumstances of either party or in the needs of the child. A change of 15% or more in the support obligation calculated under the current guidelines — using updated income figures — is presumed to constitute a substantial change sufficient to support modification. Additionally, Wisconsin requires periodic review and potential adjustment of orders every 33 months for families receiving W-2 benefits or Medicaid, which the child support agency initiates automatically. For other families, either parent must petition the court for review, presenting updated income information and requesting recalculation under the current guidelines.