Estimate Washington child support under RCW 26.19.020 — Income Shares model, current caps and percentages, with a step-by-step worked example.
| Guideline model | Income Shares |
|---|---|
| Income basis | Net (after-tax) income |
| How it works | Both parents’ incomes are combined, a basic obligation is taken from the state’s official schedule, and each parent pays in proportion to their share of combined income. |
| Caps & limits | Economic table covers combined monthly net income $2,200-$50,000 (per-child amounts by family size; presumptive through $50,000); below $2,200 support is resource-based with a $50/child minimum |
| Statute / rule | RCW 26.19.020 |
| Parameters verified | 2026-07 |
Result: $1,200 per month
Washington uses the income shares model under RCW 26.19.020: both parents’ incomes are combined, a basic obligation is determined, and each parent is responsible for their proportional share. Both parents’ incomes are combined, a basic obligation is taken from the state’s official schedule, and each parent pays in proportion to their share of combined income.
Washington calculates support on net (after-tax) income as defined in RCW 26.19.020. Economic table covers combined monthly net income $2,200-$50,000 (per-child amounts by family size; presumptive through $50,000); below $2,200 support is resource-based with a $50/child minimum.
Yes. The guideline amount under RCW 26.19.020 is presumptive, not absolute - courts may deviate with written findings for factors like extraordinary medical or educational needs, other children supported, or very high income beyond the guideline range.
Apply through the Washington child support agency or the family court in your county. Existing orders can be modified on a substantial change in circumstances - typically a significant income change, job loss, or a change in custody. The official calculator/worksheet is linked on this page (fortress.wa.gov).
Estimate only — not legal advice. Based on Washington guidelines (RCW 26.19.020), last verified 2026-07. Courts may deviate. For an official figure use the official Washington calculator.