Washington Child Support Calculator

Washington uses the Income Shares model. Washington (RCW 26.19) calculates support from an economic table based on the parents' combined net monthly income -- one of the few states using net rather than gross as the base. The table is presumptive up to $50,000/month combined net income; above that, a court may exceed the table amount only with written findings.

Washington's guideline runs on net monthly income (RCW 26.19.071). That distinction matters: entering gross income into a formula built on net income (or the reverse) produces a materially wrong figure. Most states count income from essentially any regular source -- wages, self-employment, bonuses, commissions, rental and investment income, and many benefits -- not just salary.

Not necessarily. Washington's guideline weighs each parent's share of combined income alongside the parenting-time arrangement, so a significantly higher earner can still owe support even at an even split of time.

Yes. The figure produced by Washington's Income Shares guideline is presumptive, not mandatory: a court can order a different amount when applying the guideline would be unjust or inappropriate for the specific case, and generally must state its reason on the record. Common grounds include extraordinary medical or educational expenses, a child's special needs, or costs the formula does not capture.

You have to file for a modification -- a change in your circumstances does not change what you owe on its own. Washington, like most states, requires a substantial change in circumstances: a significant involuntary income change, a change in the parenting schedule, or a material change in the child's needs. Until a court or the state child support agency issues a new order, the existing amount stays fully enforceable and arrears keep accruing, and a modification is generally not applied retroactively before the date you filed -- so filing promptly matters. In Washington, modifications are handled through DSHS Division of Child Support.

Washington publishes it directly: "Washington State Child Support Schedule (WSCSS) Worksheet Calculator — DSHS". This site's calculator is a fast estimate built on the same published guideline, not a replacement for the official form -- a court filing generally requires the state's own worksheet. The link is in the Washington Resources section on this page.