Arizona Child Support — How It Works

Arizona uses an income-shares guideline — the Arizona Child Support Guidelines — built on both parents’ incomes and parenting days. This page explains the rules and links the official court calculator; it doesn’t compute your amount.

How the Arizona formula works

The guidelines (current version effective January 1, 2022) work in steps:

Combine both parents’ gross monthly incomes;
Find the basic obligation on the schedule for that combined income and the number of children;
Split it proportionally by each parent’s income share;
Adjust for parenting time — the number of days the child spends with each parent — plus childcare and health insurance.

Parenting days, older children, and the self-support reserve

Arizona’s adjustments are what make the calculator worth using. Parenting time is counted in 24-hour blocks, and the adjustment scales with days — at roughly equal time (about 164 days each) it approaches a 50% reduction. An older-child adjustment adds 10% to the basic amount for children aged 12 and up. And a Self-Support Reserve — 80% of full-time minimum-wage earnings (about $1,685/month at the 2022 update, rising with the minimum wage) — keeps a low-earning parent above a basic-needs floor. A parent found voluntarily unemployed or underemployed can have full-time minimum-wage income imputed.

How long support lasts

Support ends the last day of the month the child turns 18 or graduates high school; if the child reaches 19 while still in high school, it ends at graduation or the 19th birthday, whichever comes first.

Use the official calculator

The Arizona Judicial Branch publishes the official Child Support Calculator (linked above). Use it for an estimate; this page only explains the model. The court that issues your order has final authority.

For a real case

The guideline amount is presumed correct but can be adjusted when it would be inappropriate. For advice on your situation, consult an Arizona family-law attorney.

Frequently asked questions

How is child support calculated in Arizona?

Arizona uses an income-shares model under the Arizona Child Support Guidelines. It combines both parents' gross incomes, finds the basic obligation on the schedule for that combined income and the number of children, and each parent pays a share adjusted by the number of parenting-time days. The current guidelines took effect January 1, 2022.

How does parenting time change the Arizona amount?

Parenting time is measured in 24-hour blocks and the adjustment scales with days: roughly equal time (about 164 days each per year) produces close to a 50% adjustment to the obligation. There is also an older-child adjustment — the basic amount rises 10% for children aged 12 and older.

Is there a low-income floor in Arizona?

Yes. A Self-Support Reserve test protects a low-earning parent: the reserve equals 80% of full-time earnings at the state minimum wage (about $1,685 a month when the 2022 guidelines took effect, and it rises with the minimum wage). If the full obligation would drop the parent below the reserve, the order is reduced.

Until what age is support paid, and can income be imputed?

Support ends the last day of the month the child turns 18 or graduates high school; if the child turns 19 before graduating, it ends at graduation or the 19th birthday, whichever comes first. A court can impute full-time minimum-wage income to a parent who is voluntarily unemployed or underemployed.

Where do I get an official estimate?

Use the Arizona Child Support Calculator linked on this page, published by the Arizona Judicial Branch. This page explains the model but does not compute an amount, and it is not legal advice.

Arizona child support guidelines