Arizona Child Support & Parenting Time Calculations

Arizona child support is based on total parenting time days

Arizona uses parenting time, or the total number of days with your children outside of school or day care, as the basis for figuring a parenting time credit in its child support formula.

Parenting time totals are a key part of the Arizona child support formula. The total number of full, half and quarter parenting time days directly affect your child support amount.  

Most parenting time totals are estimates (and thus incorrect)

Arizona attorneys and judges often rely on parenting time estimates only, even if they are incorrect, because counting total hours is tedious and time consuming. Divorcing parents often rely on these estimates as well. Neglecting significant day visits can make a big difference in totals.

Using estimates means your parenting time totals are wrong when compared to your actual parenting time schedule. This means your child support amount will not be fair or exact.

How to calculate parenting time instead of relying on estimates

To calculate parenting time totals, the easiest and most accurate way is to use software. Without software, you're forced to count full days, half days, and quarter days for a whole year. This method is error-prone when you try to figure out holidays and breaks while subtracting out the time your children spend in school or day care.

The leading parenting time calculation software, Custody X Change, can calculate your total days to see if they were estimated incorrectly.

Calculate Your Total Days Now

Using software, you can also tweak your schedule to see how even little changes, such as including quarter days (a period of 3 to 5 hours, as defined by Arizona law) affect your total number of days. you'll also see how your parenting time changes each year due to holidays and other events.

You can also track what actually happens, and show how many days you've actually received for any period of time. Historical information is a powerful tool when you request a child support modification or when you request more parenting time.

Fast facts on child support and child custody in Arizona

In any divorce, Arizona family courts award custody of the children to one or both parents. Custody is divided into legal custody and physical custody. Child support amounts are tied to physical custody designations.

Arizona sole physical custody: The children reside with and are supervised by the residential parent, while the other parent is entitled to overnight visitations. In Arizona, the number of total days that the non-residential parent has translates into an adjustment percentage, which affects the child support amount.

Arizona joint physical custody: Each parent has significant periods of physical custody, which allows them frequent and continuing contact with their children. Arizona assumes that the children will have an approximately 50/50 split between the two parents, or around 182 days each. Parenting time adjustments are not generally factored into support. Instead, the net difference between the two incomes becomes the child support amount.

Arizona child support formula and parenting time percentage

The parenting time percentage only figures into a sole physical custody case. The joint physical custody case is figured using a different formula, without offering any parenting time credit.

Sole custody formula: Arizona family courts use a formula that multiplies the non-custodial parent's adjusted income by a percentage representing the total number of days the non-residential parent hosts the children involved. The total days cannot include time when the children are with a third party, such as school or day care. Adjustments to child support are also made when each child reaches 12 years of age.

Joint custody formula: Arizona family courts use a formula that adjusts the amount of child support based on the total income for both parents, and figures out each parent's portion. The net difference between the portions results in the higher earner paying the lower earner to balance out the cost of caring for the children. Joint custody formula assumes approximately 182 days for each parent annually.

Examples of sole custody and Arizona child support

Consider the hypothetical case of Robert and Mary. Robert earns $4,000 per month, while Mary earns $2,400 per month. They have two children under age 12.

See how the child support amounts change in these examples:

  • Scenario #1: Robert is scheduled to have his children for 115 total days per year. He pays $634 in child support to Mary.
  • Scenario #2: If Robert adds just 14 more half days (defined as 6 to 11 hours) more per year, totaling 122 days, he pays $588 per month in child support to Mary.
  • Scenario #3: If Robert adds those 14 half days plus 8 full days (defined as 12 to 24 hours) totaling 130 days, he pays $508 in child support per month to Mary.
  • Scenario #4: If the children are both over 12 years old, and Robert has them for 130 days each year, he pays $594 in child support per month to Mary. This is because Arizona increases the amount of support for each child at or over 12 years old.

In Arizona, the non-residential parent pays child support to the residential parent, regardless of which parent earns more. If the custody was reversed, and Robert had sole physical custody of the children, Mary would pay child support based on her income to Robert.

Examples of the joint custody formula in Arizona child support

Consider the hypothetical joint custody case of Robert and Mary. Robert earns $4,000 per month, while Mary earns $2,400 per month. They have two children. They have agreed to an approximate 50/50 split, or around 182 days of parenting time each year.

See how the child support amounts change in these joint custody examples:

  • Scenario #1: Robert pays Mary $171 in child support because he is the higher earner.
  • Scenario #2: If one of the children is over 12 years old, Robert pays $179 in child support to Mary each month.
  • Scenario #3: If both children are over 12 years old, Robert pays $188 in child support per month to Mary.
  • Scenario#4: If Mary and Robert earned equal pay, no child support is paid or received, because the net difference between the two incomes would be $0.

In Arizona joint custody cases, generally the parent with the higher income makes the child support payments to the other parent. This is to equalize what it costs to care for the children in the two households. Parenting time is not figured into the joint custody child support formula.

Other factors in the Arizona child support formula

Arizona's child support formula uses the following information to calculate your monthly amounts for shared custody child support:

  • Overnights and day visits: A 24-hour block of time counts as one day of parenting time. However, Arizona family courts understand that day visits also count for visitations. Non-residential parents can count full days (12 hours or more), half days (6 to 11 hours), and quarter days (3 to 5 hours). Time less than 3 hours can also count as a quarter day if the parent pays for routine expenses for the children, such as meals.
  • Eligible children: Qualifying children must be under age 18, or age 19 if completing high school or general education equivalency requirements full time. Support ends upon graduation.
  • Gross earnings: Gross earnings are established based on tax records and current pay stubs. Arizona law requires the use of both parents' incomes (non-residential for sole custody and both for joint custody) from the equivalent of one full-time job to determine a child support amount.
  • Specific deductions: There are some deductions allowed by Arizona family courts that allow an adjustment of the income, including health insurance premiums for the children, support for other children and child care expenses, for example.
How accurate child support helps your children

Paying accurate child support helps your children in several ways, primarily because it ensures their financial needs are met.

Here are some other reasons why accurate parenting time totals help you, the other parent and your children:

  • It provides a fair way to determine your child support amounts
  • It guarantees the child support amount reflects each parent's responsibilities
  • It allows for modifications if your actual time and scheduled time are different
  • It is compliant with Arizona law

Your financial obligations to your children don't end with divorce, so whether you are paying or receiving child support, you owe it to your children to pay or receive the proper amount.

Top 5 things to remember about Arizona child support and overnights

To ensure you are paying or receiving the right amount of child support in Arizona, remember these 5 things:

  1. Child support in Arizona is determined by the Arizona Child Support Guidelines. These guidelines are located in Arizona Revised Statutes 25-320.
  2. Sole physical custody child support formulas include a parenting time credit based on the number of quarter days, half days and full days that the non-residential parent hosts the children.
  3. The higher the parenting time percentage, the lower the child support amount, generally.
  4. Joint physical custody child support formulas assume a 50/50 parenting time split, approximately 182 days per parent. No parenting time credits figure into the formula.
  5. Arizona child support increases whenever a child turns 12, in both sole custody and joint custody situations.

Use Custody X Change software to create a custody schedule that will quickly calculate the total overnights for the Arizona child support formula.

As you negotiate what kind of custody schedule will best fit your needs, the software will accurately calculate your parenting time percentage.


The leading parenting time calculation software, Custody X Change, can calculate your total days to see if they were estimated incorrectly.

Calculate Your Time

The leading parenting time calculation software, Custody X Change, can calculate your total days to see if they were estimated incorrectly.

Calculate Your Total Days Now