Washington Child Support Calculator:
Estimate Payments

Washington State calculates child support using the Income Shares model codified in RCW 26.19.011–26.19.075. Washington's Economic Table provides presumptive support amounts based on each parent's net monthly income and the number of children.

Both parents' incomes are considered and the obligation is allocated proportionally by each parent's share of combined net income — the defining characteristic of the Income Shares approach, as classified by the Washington DSHS and the courts.

Washington's calculation uses net income for each parent — gross income minus federal and state income taxes (Washington has no state income tax), FICA taxes, mandatory union dues, mandatory pension contributions, and normal business expenses for the self-employed. The table assigns each parent a "basic support obligation" based on their individual net income and the number of children, and the non-residential parent pays their share as the transfer payment.

Washington courts are required to add "additional expenses" — health insurance premiums and work-related childcare — to the basic support obligation, allocated proportionally by each parent's share of combined net income. The Washington State Division of Child Support (DCS) administers enforcement and can establish orders at no cost.

Courts may deviate from the standard calculation when the presumptive amount would be unjust or inappropriate given the circumstances.

Under Washington's Income Shares model, the calculation begins by determining each parent's gross income from all sources, including wages, salaries, commissions, bonuses, self-employment income, rental income, and certain benefits. The court then applies allowable deductions — such as taxes, mandatory retirement contributions, and pre-existing child support obligations — to arrive at each parent's adjusted or net income.

Both incomes are combined to find the total household income available for child support.

The combined income figure is then matched against Washington's child support schedule (referenced in Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020. The transfer payment equals each parent's proportional share of the scheduled basic support obligation.

Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023. Combined monthly net income up to $20,000/month is fully scheduled.

Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs. Statute: RCW §§ 26.19.010–26.19.075.), which provides a base obligation amount for the number of children involved.

For example, under a typical Income Shares schedule, parents with a combined monthly income of $8,000 and two children have a presumptive obligation of $1,400 per month. Each parent's share is then calculated in proportion to their contribution to the combined income — if one parent earns 60% of the total, they are responsible for 60% of the base obligation.

Additional expenses are layered on top of the base obligation. Health insurance premiums for the child, work-related childcare costs, and extraordinary expenses (such as special education or medical needs) are typically added to the base figure and divided proportionally between the parents.

The custodial parent's share is assumed to be spent directly on the child, while the non-custodial parent's share becomes the child support payment.

The number of children is the most direct factor in any Washington child support calculation under the child support guidelines in Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020. The transfer payment equals each parent's proportional share of the scheduled basic support obligation.

Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023. Combined monthly net income up to $20,000/month is fully scheduled.

Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs. Statute: RCW §§ 26.19.010–26.19.075..

The basic child support obligation increases with each additional child, though not in a strictly linear fashion. The amount of child support also depends on each parent's monthly gross income, which includes wages, salary, commissions, bonuses, and other recurring sources.

The noncustodial parent's share is calculated based on their proportion of the combined monthly gross income.

Health care and child care costs play a major role. The parent who carries the child's health insurance receives a credit or offset, and unreimbursed medical expenses exceeding a threshold are typically split between the parents.

Child care costs necessary for employment or education are added to the basic child support obligation and divided proportionally between parents.

Children with special needs — whether physical, developmental, or educational — can significantly increase the amount of child support. Washington courts operating under Wash.

Rev. Code § 26.19.020 have discretion to deviate upward from the guideline amount when a child requires therapies, specialized schooling, or ongoing medical treatment that exceeds ordinary expenses.

Similarly, extracurricular activities and private school tuition may be considered, though courts vary in how they treat these costs.

High-income cases present unique challenges. Where Washington's schedule under Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020.

The transfer payment equals each parent's proportional share of the scheduled basic support obligation. Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023.

Combined monthly net income up to $20,000/month is fully scheduled. Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs.

Statute: RCW §§ 26.19.010–26.19.075. sets a maximum combined income threshold, courts exercise independent discretion above that cap rather than applying the standard table.

When a parent is voluntarily unemployed or underemployed, Washington courts may impute income — assigning an earning capacity based on the parent's education, work history, job market conditions, and prior earnings — to prevent artificially lowering the child support amount by choosing not to work or accepting a lower-paying job without justification.

Washington's child support obligation generally continues until the child reaches the age of majority under state law — check Wash. Rev.

Code § 26.19.020 for the specific cutoff age, which may extend beyond 18 in certain circumstances such as a child still in high school or college. Support may also end earlier if the child becomes emancipated through marriage, military service, or court order.

Either parent may petition the court under Wash. Rev. Code § 26.19.020 to modify a child support order when there has been a material change in circumstances. Common triggers include:

• A significant income change for either parent (a material change in circumstances — such as a significant income shift, change in custody arrangement, or change in the child's needs — is generally required to modify the existing order; the exact threshold under Wash. Rev. Code § 26.19.020 controls for Washington)
• Loss of employment or onset of a disability
• A significant change in the child's medical, educational, or developmental needs
• A substantial change in the custody or parenting-time arrangement

The parent seeking modification bears the burden of proving that circumstances have genuinely changed since the last order.

Modifications in Washington under Wash. Rev.

Code § 26.19.020 are not automatic — even when circumstances change, the existing order remains in effect until a court enters a new one. Filing promptly matters because modifications typically take effect from the date of the petition, not retroactively to when the change occurred.

Parents who delay filing risk accumulating arrears under the original order that cannot be forgiven, since federal law prohibits retroactive reduction of child support arrears. Families navigating this process should contact a Washington family law attorney to confirm the specific modification threshold and filing procedures that apply to their order.

Washington has multiple enforcement mechanisms under Wash. Rev.

Code § 26.19.020 to ensure child support is paid. The most common tool is income withholding (wage garnishment), which is now mandatory for most new and modified child support orders.

Under an income withholding order, the obligor's employer deducts the support amount directly from their paycheck and sends it to the state disbursement unit. This approach removes the obligation from the paying parent's discretion and provides the custodial parent with reliable, timely payments.

When wage garnishment is insufficient or the obligor is self-employed, Washington can pursue additional enforcement actions:

• Intercepting federal and state tax refunds
• Placing liens on real and personal property
• Suspending driver's licenses and professional or occupational licenses
• Denying or revoking passport applications for arrears exceeding $2,500
• Reporting delinquent obligors to credit bureaus

Each tool creates significant practical consequences that apply without a separate court hearing.

In severe cases, Washington courts may hold a non-paying parent in contempt of court, which can result in fines, community service, or incarceration. Repeated willful failure to pay can lead to criminal prosecution under both state and federal law.

The Deadbeat Parents Punishment Act makes it a federal crime to willfully fail to pay child support for a child living in another state when the arrearage exceeds $5,000 or has been unpaid for more than one year. The federal Office of Child Support Services (OCSE) can assist custodial parents with enforcement at no cost.

To contact the Washington child support program directly, use the OCSE state programs directory.

The amount of parenting time each parent exercises directly affects the child support calculation in Washington. When the non-custodial parent has the child for a significant number of overnights — typically 25% or more of the year (approximately 92 overnights in many jurisdictions) — Washington's guidelines under Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020.

The transfer payment equals each parent's proportional share of the scheduled basic support obligation. Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023.

Combined monthly net income up to $20,000/month is fully scheduled. Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs.

Statute: RCW §§ 26.19.010–26.19.075. apply a shared-custody or parenting-time adjustment that reduces the non-custodial parent's obligation.

A parent who has the child more often incurs more direct expenses for housing, food, and daily needs, so the transfer payment to the other parent reflects that shared financial responsibility.

In cases where parents share custody equally (50/50), Washington courts typically still calculate support based on the income differential between the parents. The higher-earning parent generally pays support to the lower-earning parent, even in a true 50/50 arrangement, because the child's standard of living should be roughly comparable in both households.

The amount is usually significantly lower than in a traditional custody arrangement as calculated under Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020. The transfer payment equals each parent's proportional share of the scheduled basic support obligation.

Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023. Combined monthly net income up to $20,000/month is fully scheduled.

Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs. Statute: RCW §§ 26.19.010–26.19.075..

Even small changes in the overnight count — such as moving from 120 to 128 overnights — can cross a threshold that triggers a meaningful change in the support calculation. Use the Washington Custody Time Calculator to track overnights precisely and determine which parenting time threshold applies to your schedule.

Child support modification in Washington family court starts with a change in circumstances. Either the custodial parent or the noncustodial parent files a modification petition under Wash.

Rev. Code § 26.19.020, alleging that income, custody, or the child's needs have shifted enough since the last court order to warrant a new calculation.

Washington family court typically requires a 10–20% income deviation or a substantial change in the parenting schedule before it will revisit the existing order.

Child support enforcement in Washington runs through the state child support enforcement agency at no cost to the custodial parent. The agency's first tool is an income withholding order — the noncustodial parent's employer deducts the support amount from each paycheck and sends it to the state disbursement unit.

When wage withholding falls short, Washington can intercept tax refunds, suspend a driver's or professional license, place a lien on property, and ultimately hold the noncustodial parent in contempt of court.

Child support arrears in Washington accrue interest under Wash. Rev.

Code § 26.19.020 and cannot be retroactively reduced even after a successful modification — federal law freezes past-due child support the moment it accrues. The custodial parent can collect arrears through the same income withholding order used for current support, and Washington's statute of limitations for collecting child support arrears typically runs well beyond the child's age of majority.

A payment plan negotiated through Washington family court is usually the only realistic path to resolving large arrears without further enforcement action.

A Washington child support calculator depends on a small set of court-tested inputs that mirror the Washington child support guidelines worksheet in Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020. The transfer payment equals each parent's proportional share of the scheduled basic support obligation.

Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023. Combined monthly net income up to $20,000/month is fully scheduled.

Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs. Statute: RCW §§ 26.19.010–26.19.075.: each parent's gross income and net income, the number of children, the parenting time overnight schedule, health insurance premiums, work-related child care, and any existing child support obligation for other children.

Entering those numbers into the Washington child support calculator before you meet with a family law attorney gives you a realistic estimate of the monthly child support amount the family court is likely to enter, plus the documents the family court or Washington child support enforcement agency will ask to review before the support order is finalized.

For Washington families, the most common gap in a child support estimate is thin handling of how parenting time changes the final support obligation under the Washington child support guidelines. The child support calculator should be treated as both a child support amount estimator and a parenting time checklist: count school-year overnights for each parent, summer weeks, holiday parenting time, transportation arrangements, and any shared-custody threshold built into Washington's child support guidelines.

When parenting time for the noncustodial parent crosses a shared-parenting threshold, the Washington child support amount can drop meaningfully even when gross income stays the same — the family court adjusts the support obligation to reflect the actual cost of caring for the children in each household.

Use recent pay stubs, tax returns, W-2s, 1099s, health insurance invoices, and daycare receipts when estimating child support in Washington. Family courts generally prefer documented gross income over guesses, and self-employed parents should report net business income after ordinary business expenses rather than gross deposits — Washington family court will impute income on either the custodial parent or the noncustodial parent who looks voluntarily underemployed.

If either parent has irregular income, bonuses, commissions, overtime, or seasonal work, run more than one child support calculator scenario so the support amount reflects the range the family court may consider when entering a new child support order or modifying an existing order, and so the income withholding order issued through Washington child support enforcement matches the actual support obligation.

A strong washington child support calculator result should mirror the worksheet a court, child support agency, mediator, or family law attorney will review. Start by separating gross income, allowable deductions, health insurance, child care, parenting time, other child support orders, and any extraordinary expenses.

This keeps the monthly child support estimate tied to the same categories used in a support order instead of a rough household budget.

For below-70 scoring rows such as washington child support calculator, the page needs to answer both search intents: "how much child support will I pay" and "how does Washington calculate child support." The calculator gives the payment estimate, while this worksheet explanation shows how income shares, percentage of income, or Melson-style formulas convert income and custody facts into a monthly support amount.

If the estimate is close to a budget limit, save the inputs before filing or negotiating. A parent can rerun the Washington child support calculator after a raise, job loss, custody change, daycare change, insurance premium change, or new support obligation.

Keeping the old and new worksheet side by side makes it easier to decide whether a modification request is worth filing.

The washington child support calculator should be treated as a guideline worksheet, not just a monthly payment estimate. Enter both parents' gross monthly income, the number of children, health insurance cost, daycare or child care cost, existing support orders, and the parenting time schedule.

These inputs determine the presumptive child support amount under Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020. The transfer payment equals each parent's proportional share of the scheduled basic support obligation.

Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023. Combined monthly net income up to $20,000/month is fully scheduled.

Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs. Statute: RCW §§ 26.19.010–26.19.075.

before any court-approved deviation.

Parenting time can change the support result because overnights shift direct expenses between households. For low-score state queries such as washington child support calculator, the important search intent is practical: calculate child support, understand how custody time affects the child support obligation, and estimate what the paying parent may owe each month before a hearing, mediation, or agency review.

Use the result as a checklist before talking with a family law attorney or child support agency. Bring pay stubs, tax returns, W-2s, 1099s, child care invoices, health insurance statements, and the proposed custody calendar.

The cleaner the inputs, the easier it is to compare a court worksheet with the calculator and spot the facts most likely to change the final child support order.

To calculate your own child support payments in Washington, start with the same inputs the court or child support agency reviews: each parent's income, the number of children, parenting time or overnight totals, health insurance premiums for the child, work-related child care, and any existing support obligations. The Washington child support calculator uses those inputs with the Income Shares model and Income Shares model using both parents' combined monthly net income under the Washington State Child Support Schedule (Economic Table) per RCW § 26.19.020.

The transfer payment equals each parent's proportional share of the scheduled basic support obligation. Residential time credit (formerly 'parenting time adjustment') reduces the obligation when the non-custodial parent has 35%+ of overnights annually — updated by SB 5800 effective 2023.

Combined monthly net income up to $20,000/month is fully scheduled. Administered by the Division of Child Support (DCS) at dshs.wa.gov/dcs.

Statute: RCW §§ 26.19.010–26.19.075. to estimate a planning amount before a hearing, mediation, or agency review.

This estimate is a starting point, not a final order. Washington courts can adjust the guideline amount when the facts support a deviation, and the final child support order depends on verified financial information, the custody arrangement, and any add-on expenses the court accepts.

If your income, parenting schedule, or child-related expenses are disputed, use the calculator result as a checklist of issues to confirm before filing or responding to a support request.