Washington Child Support Calculator 2026

Both parents’ monthly net incomes are combined and looked up on the RCW 26.19.020 economic table, which prints a dollar amount per child. Multiply by the number of children for the basic support obligation, then split it in proportion to each parent’s share of the combined net income. The parent without primary residential time pays their share as the transfer payment, plus their share of day care and health insurance.

Almost everything with a number in it. EHB 1014 replaced the economic table for orders entered on or after January 1, 2026: the new table runs from $2,200 to $50,000 of combined monthly net income instead of $1,000 to $12,000. The self-support reserve rose from 125 percent to 180 percent of the federal poverty level, which is $2,394 a month on the 2026 guideline. And PFML and WA Cares premiums now count as deductions when figuring net income. Results from tools still using the old table do not match current law.

Not automatically. RCW 26.19.075(1)(d) lets a court deviate from the standard calculation when the children spend a significant amount of time with the paying parent, but the statute gives no formula, no overnight thresholds, and no percentages. The court weighs the changed expenses in both homes and must make written findings, and it may not deviate at all if that would leave the receiving household unable to meet the children’s basic needs or if the children receive TANF. That is why this calculator does not ask for overnights.

Two guardrails at the low end. The basic obligation may not reduce the paying parent’s net income below 180 percent of the federal poverty level for one person, $2,394 a month using the 2026 figure. But even below that line, the statute presumes an order of at least $50 per child per month unless the paying parent shows that would be unjust. A parent netting $2,420 with one child would pay $26 under the reserve alone, so the $50 floor sets the order instead.

The table stops in both directions. Above $50,000 the amount at the $50,000 row is presumptive, and a court may exceed it only with written findings of fact; the Washington Supreme Court held in McCausland that judges may not simply extend the table’s pattern upward. Below $2,200 there is no row: the obligation comes from the resources and living expenses of each household, not less than $50 per child. This tool shows the floor and says the court sets the actual amount.

Use it with care. As of our August 8, 2026 check, the DSHS Quick Child Support Estimator still asks how many children are under age 12. That question mattered under the pre-2026 table, which had two age bands; the table EHB 1014 put in force on January 1, 2026 has a single set of per-child amounts with no age split. DSHS’s full worksheet calculator is reported updated for the new law. For a filing-grade number, use the full calculator or the AOC worksheets rather than the quick tool.

Gross income from nearly all sources, minus the RCW 26.19.071(5) deductions: federal and state income taxes, FICA, mandatory pension payments, mandatory union or professional dues, industrial insurance premiums, PFML and WA Cares premiums, court-ordered maintenance actually paid, up to $5,000 a year of qualifying voluntary retirement contributions, and business expenses for the self-employed. A new spouse’s income, TANF, and SSI stay out entirely, and overtime beyond 40 hours a week gets special treatment under the 2025 amendments.

In two ways, neither of them a deduction from income. Support the parent pays under other orders counts toward the 45 percent whole-family limit of RCW 26.19.065(1): all obligations together may not top 45 percent of net income absent good cause, so a large prior order can cap the current one. Children from other relationships are also a deviation ground under RCW 26.19.075(1)(e), which a court applies with written findings.