Child support calculators / Washington
Washington child support
calculator
Free guideline estimate under Washington's official child support guidelines (controlling authority: RCW 26.19.020). Built for family law attorneys and their staff. No account required, and nothing you enter is stored.
Overnights always total 365, so changing one side updates the other.
Get the line-by-line worksheet free for 14 days, with the guideline edition and citation (RCW 26.19.020)
- Printable worksheet with the full line-by-line calculation
- Guideline edition and controlling-authority citation on the printout
- Adjustments detail: parenting-time credit, add-on allocation, deductions
- Save calculations to matters, plus spousal support and property division
14-day free trial · credit card required · every feature included · see pricing
Informational estimate for licensed attorneys and their staff — not legal advice, not a guarantee of any court outcome. Verify against your jurisdiction’s official guidelines worksheet before relying on it.
How Washington calculates child support
Washington's child support guidelines are established by RCW 26.19.020. Washington uses the income shares model, which combines both parents’ incomes and allocates the basic support obligation between them in proportion to each parent’s share of the combined income.
This calculator applies the current guideline edition: RCW 26.19.020 economic table, eff. 1/1/2026 (2025 c 272).
The result is the presumptive guideline amount, the starting point a Washington court uses before considering deviation factors. The full line-by-line worksheet, guideline edition, and statutory citation are available in Aequis with a 14-day free trial (credit card required).
Washington child support FAQ
How is child support calculated in Washington?
Washington sets child support under its official guidelines (RCW 26.19.020), which follow the income shares model. The guideline produces a presumptive monthly amount from the parents' incomes, the number of children, and inputs such as parenting time, childcare, and health insurance costs.
Is this the exact amount a Washington court will order?
No. This is an informational estimate of the presumptive guideline amount. Courts can deviate based on statutory factors, and official worksheets may require inputs this calculator does not collect. Always verify against the official guidelines worksheet before relying on any number.
What income counts for child support in Washington?
Guidelines generally start from each parent's gross income from most sources, with their own definitions, exclusions, and deductions. This calculator uses gross monthly income; consult RCW 26.19.020 for what Washington includes.
Do overnights affect child support in Washington?
Many jurisdictions adjust the obligation for parenting time once overnights pass a threshold, and this calculator applies Washington's guideline treatment of overnights where the guideline provides one. The exact effect depends on Washington's formula and the parents' incomes.
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CaseForward is a self-help document-preparation service, not a law firm, and does not provide legal advice.
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