## How is child support calculated in Wisconsin? Wisconsin uses the **Percentage of Income model**. Here's how it works. The non-custodial parent's income is multiplied by a fixed percentage (set by statute and tied to the number of children) to produce the support amount. The other parent's income generally doesn't enter the calculation. Simpler than income shares — but less responsive to dual-earner realities. **Worth knowing about Wisconsin:** Wisconsin uses a percentage of gross income: 17% for 1 child, 25% for 2, 29% for 3, 31% for 4, 34% for 5+. Adjustments for shared placement (via the "shared placement formula"). ## What goes into the calculation Most states' guidelines start from gross income (with statutory adjustments) and account for: - Wages, salaries, commissions, bonuses, overtime - Self-employment net income - Pension, retirement, and Social Security benefits - Rental and investment income - Unemployment, workers' comp, disability - Imputed income if a parent is voluntarily unemployed/underemployed Standard deductions before the support formula runs: - Federal/state income tax - Social Security and Medicare (FICA) - Mandatory union dues - Health insurance premiums for the child - Other court-ordered support obligations ## Add-ons most states bolt onto the base number - **Health insurance** for the child (split proportionally to income) - **Childcare costs** (work-related daycare) - **Uninsured/extraordinary medical expenses** - **Educational expenses** (private school, tutoring) — case-by-case - **Visitation travel costs** — for long-distance parents in some states ## Shared parenting time can change the math Most states reduce the support payment as the non-custodial parent's overnight time goes up — but not in a smooth, linear way. Many states have "cliffs" at specific overnight thresholds (e.g., 30%, 40%, 50%) where the formula switches from a standard payment to a shared-time formula. Whether you cross a threshold by even one overnight a year can change support by hundreds of dollars per month. ## Deviation from the guidelines The number the formula produces is a **rebuttable presumption**, not a hard floor or ceiling. Either parent can ask the court to deviate up or down by showing factors like: - A child's special medical or educational needs - Extraordinary income or expenses outside the formula - A parent's significant other obligations - A parenting plan that already addresses costs differently Most judges stick close to the guideline, but meaningful deviations happen when the facts justify them. ## Modifying support later Child-support orders aren't permanent. Most states allow modification when there's a **substantial change in circumstances** — usually a change of 15%+ in either direction. Common triggers: - Job loss or significant pay cut (or significant raise) - A change in custody/parenting time - A child's emancipation - New medical needs - A parent retires ## Enforcement is aggressive Once a child support order is in place, ${s.name}'s child-support enforcement agency has powerful tools: - Income withholding directly from paychecks - Tax refund interception (federal and state) - Driver's license suspension - Professional license suspension - Passport denial - Liens on real and personal property - Contempt of court — including jail ## What you should do Run the numbers BEFORE you agree to anything. Most Wisconsin family-law attorneys can pull up the state's guideline calculator and produce a realistic estimate in minutes. Going in blind to a settlement conference — or worse, to court — without knowing what the formula says is a recipe for an avoidable bad outcome. --- *This guide is general information about Wisconsin law as of early 2026 and is not legal advice. Child-support guidelines are revised periodically and individual cases involve detail-heavy calculations. Talk to a licensed Wisconsin family-law attorney about your specific situation.*