Washington Child Support Calculator

Washington uses the income shares model. Washington uses the Income Shares Model under Chapter 26.19 RCW and the Washington State Child Support Schedule. Both parents' net incomes are combined to determine the Basic Child Support Obligation from the Economic Table (RCW § 26.19.020). Each parent's share is proportional to their percentage of combined net income. The Economic Table is presumptive for combined monthly net incomes up to $50,000. Neither parent's obligation may exceed 45% of net income except for good cause. Adjustments are made for residential schedule, health insurance, daycare, and other special expenses. Effective January 1, 2026, the self-support reserve increases from 125% to 180% of the federal poverty level.

Gross income from all sources is typically used, including wages, salary, bonuses, commissions, self-employment income, rental income, investment income, Social Security benefits, unemployment benefits, and disability benefits. Courts may also impute income if a parent is voluntarily unemployed or underemployed.

Child support in Washington generally continues until the child turns 18, or through high school graduation if the child is still in school. Some orders extend to age 19 or 21 depending on the state and circumstances (college support, special needs).

Yes, child support orders in Washington can be modified when there is a substantial change in circumstances. Common reasons include significant income changes (job loss, promotion), changes in custody arrangement, changes in the child's needs, or changes in healthcare costs.

Washington has enforcement mechanisms including wage garnishment, tax refund interception, license suspension (driver's and professional), bank account levies, contempt of court charges, and reporting to credit bureaus. Failure to pay can result in fines and jail time.