Washington Child Support Calculator
Calculate estimated child support using Washington's official guidelines
About Washington's Guidelines
Income Shares Model
Note: Uses net income with residential credit
Key Information
- •Model: Income Shares
- •Income Cap: $12,000/month combined
- •Last Updated: January 15, 2024
Common Deviation Factors
Monthly Income
Children & Custody
Additional Monthly Expenses
Estimates only — not legal advice. Consult a Washington family law attorney for official calculations.
Official Washington Court Forms
Download official court forms from the Washington judiciary website. These are free, legally valid forms for your family court case.
Child Support Forms
Official petitions & worksheets
Modification Forms
Request changes to orders
Financial Disclosure
Income & expense statements
Parenting Plan
Custody & visitation schedule
These links go to official Washington court websites. Forms are free and provided by the state judiciary.
Washington Child Support Guidelines
Washington uses the Washington State Child Support Schedule (RCW 26.19) to determine child support obligations. Under the Income Shares model, both parents' incomes are combined to estimate what the family would have spent on the child if the household were intact. The obligation is then divided proportionally based on each parent's contribution to combined net income.
Washington has several distinctive features in its child support system. Washington uses the "Whole Family Formula" — a unique approach that considers the entire family unit including children from other relationships. Residential credit applies at 92+ overnights (25%) using a transfer payment formula based on the Economic Table. Washington has a detailed "Economic Table" maintained by the legislature that forms the basis of all calculations.
Washington bases calculations on net income — meaning income after mandatory deductions like taxes, Social Security, and Medicare. This gives a more accurate picture of each parent's take-home pay. The self-support reserve in Washington is $1,425/month, ensuring the paying parent retains enough income to cover basic living expenses.
How Washington Calculates Child Support
Washington follows a 6-step process under the Washington State Child Support Schedule (RCW 26.19):
- 1
Calculate each parent's net monthly income (after taxes)
- 2
Combine net incomes and find the basic support obligation from the Economic Table
- 3
Each parent's share = their percentage of combined net income
- 4
Apply the residential credit if the non-custodial parent has 92+ overnights
- 5
The residential credit formula considers the children's direct costs during each parent's time
- 6
Add health insurance and daycare costs proportionally
Income Thresholds & Key Numbers in Washington
Maximum Income Cap
$12,000/mo
Self-Support Reserve
$1,425/mo
Shared Custody Threshold
92 nights/yr
25% of overnights
Income Basis
net
Sample Obligation Schedule
| Combined Monthly Income | 1 Child | 2 Children | 3 Children |
|---|---|---|---|
| $1,500 | $255 | $370 | $442 |
| $3,000 | $462 | $672 | $815 |
| $5,000 | $672 | $985 | $1,198 |
| $8,000 | $930 | $1,372 | $1,668 |
| $12,000 | $1,208 | $1,785 | $2,172 |
* Simplified schedule. Actual amounts may vary based on additional factors.
Custody Time Adjustments in Washington
Washington recognizes "Residential Credit (Whole Family Formula)" when the non-custodial parent has the children for at least 92 overnights per year (approximately 25% of the time). When this threshold is met, the standard child support formula is adjusted to reflect the increased direct expenses borne by both parents.
Under Washington's Income Shares approach, the shared parenting adjustment typically calculates each parent's obligation based on their income share, then applies a credit or cross-calculation that accounts for the time each parent directly supports the child. The more overnights the non-custodial parent has, the greater the reduction in their payment — but the adjustment is not dollar-for-dollar because fixed costs like housing don't decrease when the child is away.
Below 92 overnights, Washington generally treats the arrangement as a sole custody situation with standard visitation, and no custody time adjustment is applied to the child support calculation.
Frequently Asked Questions About Washington Child Support
What is the Economic Table in Washington?
What is the Whole Family Formula?
What is the income cap in Washington?
How to Reduce Child Support Costs in Washington
While child support is determined by Washington's guidelines, there are legitimate ways to ensure your obligation is calculated fairly.
Increase Parenting Time
In Washington, more overnights with your children can reduce your support obligation. Document actual time spent and request a formal custody modification if needed.
Ensure Accurate Income Reporting
Both parents' incomes must be reported accurately. Verify that bonuses, overtime, and variable income are averaged correctly over the appropriate period.
Claim All Allowable Deductions
Washington allows deductions for items like mandatory retirement contributions, union dues, and health insurance premiums. Make sure all qualifying deductions are included.
Request a Modification When Eligible
If your income has decreased by 15-25% or more, you may qualify for a modification. File promptly — changes are typically not retroactive before the filing date.
Account for Other Children
If you have other children you're legally obligated to support, this can be factored into the calculation as a deduction in most states.
Review Healthcare & Childcare Costs
Ensure shared expenses like health insurance and childcare are divided proportionally. If costs have changed, update the court.
Key Facts About Child Support in Washington
Calculation Model
Income Shares
Guidelines Source
State Statute
Review Frequency
Every 4 Years
Income Cap
$12,000/mo
Last Updated
January 15, 2024
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