Arizona uses a standardized calculator—essentially a spreadsheet—to calculate child support based on statewide guidelines. This is a great starting point for parents looking to estimate child support before or during family court litigation, but it is important to understand that the calculator is only as accurate as its inputs. Those often can be more complicate than you might think.
What goes on the Arizona Child Support Calculator
The publicly available tool is built as a questionnaire to make it easier for the public to use, but family lawyers and judges use a spreadsheet that considers the following inputs:
Income
The first big factor that impacts child support is, as you might expect, how much income each parent earns. Income for child support purposes can be very different from taxable income. For child support, the Arizona Child Support Guidelines define income to include cash or cash like benefits from all sources, including:
- Wages, salaries, commissions, bonuses
- Employer contributions to employee benefits
- Investment returns, capital gains, dividends, interest
- Trust income, annuities
- Rental proceeds, royalties
- Severance pay, unemployment benefits
- Pensions, retirement benefits, social security benefits
- Workers' compensation benefits, disability benefits
- Military pay, military disability benefits
- Recurring gifts or contributions from others
- Spousal maintenance received
Because income directly impacts how much child support someone will pay and what constitutes income extends well beyond ordinary wages, this is frequently a big source of conflict in child support cases.
To complicate things further, family courts can attribute earning capacity to a parent believed to be earning less than they are capable of earning. So the number on the child support worksheet sometimes appears completely made up.
Parenting time
Parents are often surprised to learn that parenting time can have an even bigger impact on child support than income. The basic idea is that the less parenting time a parent exercises, the more they should pay through child support to equalize the support each parent provides to the children.
Even very minor differences in parenting time can meaningfully impact the child support calculator. This is because the guidelines use a parenting time table that applies a different adjustment percentage based on ranges of parenting time. The current table is recreated below.
As you can see, the calculator's credit for parenting time is non-linear and even as little as a one-day difference can change the child support obligation. In one of the more extreme examples, a parent going from 34 days to 35 days of parenting time literally doubles the adjustment percentage. The adjustment percentage is a multiplier that, as it goes up, it reduces a parent's child support obligation.
Another issue with parenting time is how to count fractional parenting time because it is not just overnights that count. When parents exercise less than 24 consecutive hours of parenting time, they are credited like this:
- A period of 12 hours or more counts as 1 day;
- A period of 6 to 11 hours counts as a 1/2-day;
- A period of 3 to 5 hours counts as a 1/4-day; and
- Periods of less than 3 hours may count as a 1/4-day if, during those hours, the parent with less parenting time pays for routine expenses of the child, such as meals.
Perhaps counterintuitively, we are not strictly counting the time children are physically with a parent either. A parent who delivers a child to school receives credit for the time in school until the other parent starts their parenting time.
A very common application of this is a weekday overnight for a parent who exercises less than equal parenting time. They would receive credit for the time their parenting time begins until the time the other parent begins their parenting time after the next school day.
Judges frequently make simple mathematical mistakes when calculating parenting time that can meaningfully change child support. If your parenting plan involves less than equal parenting time, you definitely should consult with an experienced family lawyer to talk about how child support should be calulated.
Expenses incurred for the children
There are four main categories of expenses that can go on the child support worksheet:
- Health/dental/vision insurance premiums incurred for the children
- Childcare expenses
- Education expenses (like tuition, not school supplies or clothing)
- Extraordinary expenses (usually for gifted or special needs children)
Family courts are only required to include the insurance costs. The other categories of expenses are totally discretionary, meaning the judge decides whether to include those. With childcare commonly costing thousands of dollars per month, this is a really important part of the calculus.
The way the worksheet works is that any expenses added to a parent's column are allocated between the parents consistent with each parent's proportionate share of income. To make this simpler, imagine a situation where Parent A earns $50,000 per year and Parent B earns $100,000 per year. Together, they earn $150,000 with Parent A earning one third of that and Parent B earning two thirds of that. This means that if either parent is credited with expenses for the children, Parent A will be responsible for one third of those expenses and Parent B will be responsible for two thirds.
Continuing this illustrative example, now imagine that Parent A incurs $1,800 per month in childcare expenses. If the judge declines to include those on the worksheet, Parent A is responsible for the full $1,800. If the judge includes the childcare costs, Parent A's responsibility effectively becomes $600 (or one third), based on the parties' combined incomes. This means that Parent B's child support obligation would increase by $1,200. It is easy to see why child support cases can become very contentious.
Note: extracurricular activities are generally NOT built into the child support worksheet. This makes it very important for parents to make sure that their parenting plan contains language regarding the division of these expenses.
Other factors
The age of children subject to the child support order and the number of other children each parent supports can also impact the child support calculation. Courts may require proof of a child support obligation a parent is paying before crediting that parent with support of other children not common to the parties. This is another discretionary area where having a good lawyer can change the calculus in your favor.
The calculator is a starting point
While the child support calculator is meant to provide predictability and consistency in child support cases, family courts are not strictly bound to its calculation. In situations where the court believes the calculator would be unjust, it can deviate—meaning the court can increase or decrease child support as it deems appropriate. Child support deviations can occur for many reasons, but are most common in cases where the child support amount would be very small or, conversely, in high net worth cases where the child support calculator inadequately factors the child's standard of living and a parent's ability to provide more financial support.
Conclusion
The Arizona Child Support Calculator is a great tool for estimating potential child support. However, all of these moving parts lead to considerable variability in child support cases and make it very important for parents to fully understand how the child support calculator works. Ensuring that the inputs are accurate—and that the results are interpreted within the full context of the case—can make a meaningful difference in achieving a fair and appropriate outcome. The best way to do this is to schedule a free consultation with one of our experienced child support lawyers. We can answer any questions you have about the Arizona Child Support Calculator and help you understand how support might be calculated in your case.
