Wisconsin Child Support Calculator

Standard child support calculations:

• 1 child: 17% of parent's income
• 2 children: 25% of parent's income
• 3 children: 29% of parent's income
• 4 children: 31% of parent's income
• 5 or more children: 34% of parent's income

Shared-placement child support formula:

This is applicable if children live with each parent at least 25% of the time, or 92 days each year. In these situations, child support is calculated as follows:

• 1. Child support is determined for each parent using the percentages above.
• 2. Each parent's child support amount is multiplied by 150%.
• 3. The amount of child support for each parent is multiplied by the percentage of time the other parent has with the children.
• 4. The lower amount is subtracted from the higher amount. The result is the amount that the parent with the higher amount will pay to the parent with the lower amount.

If the number of days children stay with Parent A is less than 92, child support can be calculated by applying the appropriate percentage to their income. However, if the number of days children stay with each parent is 92 or higher, the shared-placement child support formula described above should be used.

Updates to Child Support Laws

Under a law that went into effect on January 1, 2026, parents will be required to provide each other with financial information that could affect existing child support orders. If either parent has experienced a change in employment or a significant change in the income they earn, they are required to notify the other parent within 10 days. If necessary, steps may be taken to adjust child support orders based on these changes. This is meant to ensure that child support orders will accurately reflect the financial circumstances of both parties.