Wisconsin Child Support Guidelines: How Support Is Calculated

In Wisconsin, child support is calculated first as a flat percentage of the paying parent's gross income: 17% for one child, 25% for two, 29% for three, 31% for four, and 34% for five or more children. That percentage standard shifts if both parents share substantial placement time, if the paying parent's income is very high or very low, or if the paying parent already owes support for a child from another relationship. An existing order can later be revised if circumstances substantially change, and Wisconsin treats 33 months since the last order as a built-in trigger for reviewing that question.

How Wisconsin Calculates Basic Child Support

Wisconsin's child-support system is built around a percentage-of-income standard rather than a complicated income-shares grid. Under this standard, the payer's share of gross income owed as support depends on the number of children being supported:

• 17% of income for 1 child
• 25% of income for 2 children
• 29% of income for 3 children
• 31% of income for 4 children
• 34% of income for 5 or more children

This percentage standard is the default starting point in most cases, but several situations move a case off the flat percentage and onto a different calculation, described below.

When Parents Share Placement

Wisconsin's guidelines recognize that raising a child across two households costs more than raising a child in one household, so the calculation changes once placement is genuinely shared. The shared-placement formula applies when both parents have court-ordered placement of at least 25% of the year, which works out to 92 or more overnights annually. A parent who meets that threshold is treated as a "shared-placement parent."

Under the shared-placement approach, each parent's percentage-standard amount is first multiplied by 150% to account for the duplicated basic costs of maintaining two homes for the child. That adjusted figure is then offset against the other parent's adjusted figure based on each parent's actual share of placement time, producing a net support amount. Because this calculation involves more moving parts than the basic percentage standard, it's worth asking the court or a family court commissioner to walk through the shared-placement worksheet with your specific placement schedule and income figures rather than estimating it yourself.

High-Income and Low-Income Adjustments

The standard percentages are not applied without limit at either end of the income scale.

Higher-income payers

For payers with higher incomes, Wisconsin scales back the percentage above certain monthly income thresholds. The full standard percentages apply to income up to $7,000 per month. For the portion of income between $7,000 and $12,500 per month, reduced rates apply: 14% for one child, 20% for two, 23% for three, 25% for four, and 27% for five or more. Above $12,500 per month, the rates step down further to 10%, 15%, 17%, 19%, and 20% for one through five-or-more children, respectively.

Lower-income payers

At the other end, a payer whose income falls below 150% of the federal poverty guidelines may have support set using reduced percentages from a separate low-income table rather than the standard percentages. Because federal poverty guidelines are updated periodically, don't assume you know where that line currently sits — ask the court or your local child-support agency to confirm the current threshold and reduced rates that would apply to your income.

Support for children from more than one relationship

If a paying parent already has a prior legal child-support obligation for a child from a different relationship, that existing obligation is subtracted from the parent's income before support for the new child is calculated. This keeps a parent's total support obligations from being calculated as if the prior obligation didn't exist.

What Counts as Income

Wisconsin defines gross income for child-support purposes broadly. It includes wages, salaries, tips, commissions, bonuses, self-employment income, interest, dividends, and many other types of benefits. If part of your income comes from a less common source — for example, irregular self-employment earnings or a particular type of benefit — don't assume it's excluded; ask the court or child-support agency how that specific income should be counted, since the definition is intentionally wide-reaching.

Changing a Wisconsin Child Support Order

Time-sensitive note: An existing Wisconsin child-support order isn't permanent. It can be revised when a parent shows a substantial change in circumstances since the last order — for example, a significant change in either parent's income or in the placement schedule. Wisconsin also builds in an automatic trigger for revisiting this question: once 33 months have passed since the most recent order, the law creates a rebuttable presumption that a substantial change in circumstances has occurred, making it easier to bring the order back before the court for review. That 33-month presumption does not apply, however, when the existing support is expressed as a percentage of income rather than a fixed dollar figure. If your order is coming up on that 33-month mark, or your circumstances have changed significantly for any other reason, that's a signal to look into a modification rather than assume the existing order will always apply.

How Wisconsin Enforces Child Support

Child-support enforcement in Wisconsin doesn't rely only on state law — it's backed by a federal framework that every state, including Wisconsin, is required to adopt as a condition of federal funding. That framework requires the state to run a dedicated child-support enforcement agency and gives it standardized tools such as automatic income withholding, license suspension, and liens against a non-paying parent's property. Federal law also waives sovereign immunity so that even federal wages and certain federal benefits can be garnished to pay support.

If the parents live in different states, a separate federal rule steps in as a tie-breaker: other states are required to enforce a validly issued Wisconsin child-support order, and, with narrow exceptions for continuing jurisdiction, another state generally cannot modify it. This works alongside Wisconsin's adoption of the interstate child-support enforcement framework used across the states, so a support order doesn't lose its force just because one parent moves away.

Child Support and Bankruptcy

A common concern is whether a parent can escape child support by filing for bankruptcy. Under federal bankruptcy law, a "domestic support obligation" — which includes child support and spousal support — cannot be discharged in bankruptcy and is paid ahead of most other unsecured debts. Property-settlement debts owed to a former spouse under a divorce decree are also generally treated as non-dischargeable in a typical Chapter 7 bankruptcy case. In practice, this means falling behind on Wisconsin child support is not a debt that disappears through bankruptcy.

What You Can Do in Wisconsin

1. Identify which calculation applies to your situation. Figure out whether your case fits the standard percentage, the shared-placement formula (25%+ placement for both parents), or a high-income or low-income adjustment, since each uses different numbers.
2. Gather income documentation. Because Wisconsin's definition of gross income is broad, pull together pay stubs, self-employment records, and documentation of any other income sources so the calculation is based on accurate figures.
3. Confirm your placement schedule in writing. If placement is shared or close to the 25%-of-the-year threshold, get the actual court-ordered overnight schedule clear, since that determines whether the shared-placement formula applies.
4. Ask about prior support obligations. If you already pay support for a child from another relationship, raise this directly so it's properly subtracted before your new support amount is set.
5. Use the county's resources. Your county's family court commissioner or child-support agency can run the specific worksheet for your income and placement situation rather than you estimating it from percentages alone.
6. Track the 33-month mark. If your order is a fixed dollar amount and it's been close to 33 months since it was last set, that's a natural checkpoint to review whether circumstances have changed enough to justify a modification.
7. Act early on enforcement problems. If support isn't being paid, contact the child-support agency promptly — income withholding and other enforcement tools are more effective the sooner an arrears problem is addressed.

This article is general information, not legal advice — confirm current numbers and how they apply to you with the Wisconsin court or a licensed attorney.