Washington Child Support Calculator 2026

Washington uses the income shares model. The basic support obligation is read from the economic table in RCW 26.19.020 using the parents' combined monthly net income and the number of children, and each parent is responsible for a share equal to that parent's share of the combined income. This calculator contains the full table that took effect on January 1, 2026 (479 rows from $2,200 to $50,000) and follows the standard calculation on the state worksheets, including the low-income limits.

How Washington Child Support Is Calculated

Net income is gross income less federal and state income taxes, Social Security and Medicare, mandatory pension payments, mandatory union or professional dues, state industrial insurance and other mandatory state deductions, court-ordered maintenance actually paid, up to $5,000 a year of voluntary retirement contributions, and normal business expenses for the self-employed (RCW 26.19.071). This page does not work net income out, so enter the net figure. The table gives an amount per child, which is multiplied by the number of children and then by the paying parent's share of combined income.

The amounts above are per child. The state's online calculator rounds combined income to the nearest $100 row, and this page does the same. The table is presumptive up to $50,000 of combined income; above that the $50,000 row is used and the court may order more on written findings. With net incomes of $40,000 and $20,000 and three children the standard calculation is $5,387 a month.

Worked Example Checked Against the State Calculator

A paying parent has $5,000 of monthly net income and the other parent $3,000, with two children. Combined income is $8,000, the table gives $960 per child, or $1,920 in total, the paying parent's share is 62.5% and the standard calculation is $1,200 a month. The Division of Child Support's own calculator code returns the same figure. Add $400 of day care paid by the other parent, $100 paid by the paying parent and a $150 premium paid by the paying parent, and the standard calculation becomes $1,356.

Low-Income Limits and Shared Costs

The self-support reserve is 180% of the federal poverty guideline for one person, which is $2,394 a month in 2026. A paying parent with net income below it owes the presumptive minimum of $50 per child a month. Above it, the basic obligation may not take that parent's income below the reserve: with $2,600 for the paying parent, $3,000 for the other parent and two children the share of the table amount is $721, but the limit cuts it to $206 (RCW 26.19.065). When combined income is under $2,200 the table does not apply and the minimum of $50 per child is shown.

Health care and day care costs are not in the table. They are shared in the same proportion as the basic obligation, and a parent who pays one directly gets credit for it (RCW 26.19.080). The law also says a parent's support for all of his or her children may not exceed 45% of net income except for good cause; the page shows that figure for information.

What This Page Does Not Do

• It does not adjust for the time the children spend with the paying parent. In Washington that is a deviation from the standard calculation which only the court can decide (RCW 26.19.075).
• It does not work out net income from gross pay, and it does not handle children from other relationships, split custody or more than five children.
• It does not apply the 45% limit automatically, because the court decides whether the limit or a good-cause exception applies.
• It leaves out uninsured medical costs, tuition and long-distance travel, which are shared in the same proportion when the court orders them.

Estimate Only: Who Sets the Washington Order

This page gives an estimate only — the court or the state child support agency sets the order, and either can depart from the guideline where the law allows. Before relying on any figure, run the same figures through the Washington State child support schedule calculator. The governing text is RCW 26.19.020, the child support economic table effective January 1, 2026.

If your income, the parenting schedule or the children's needs change, ask the court or the agency to review the order, and keep paying the ordered amount until it is changed. Last updated: October 2026.