"Basic" Child Support Formula

Basic child support is a monthly payment from the "non-custodial parent" to the "custodial parent."

Note that there are two types of child support:

  • "Basic" support is the regular payment that one parent makes to the other in most cases.

  • Additionally, the parents will share "add-ons" support, meaning educational expenses, health related expenses, and expenses for the child's extra-curricular activities and child care. These costs are apportioned based on the parent's respective incomes / earning capacities and paid separately.

The Child Support Standards Act (CSSA) sets the formula for "basic" support, although parents are free to, and often do, deviate from the formula and make their own arrangements.

The formula directs the non-custodial parent to remit a certain percentage of qualifying income to the other parent:

  • Seventeen percent (17%) for one child.
  • Twenty-five percent (25%) for two children.
  • Higher percentages (29% to 35%) for three or more children.

Q: What is qualifying income?

Qualifying income is gross income from all sources, minus a few deductions, most notably FICA taxes and local taxes. It includes investment income, gifts from relatives, etc.

Income is presumptively capped at 141,000, although the court can choose to apply the statute above that amount, if appropriate. As a practical matter, courts usually apply the statute to around 250,000 or 300,000 of combined income (see below).

Q: How is the "basic" support calculated?

The calculation is actually a little complicated. First, the court determines the combined parental income - that is, it adds together the incomes of both you and your spouse. It applies the child support percentage to the first 141,000 of combined income. Then it determines whether to apply to the statute to income above that amount, which it usually will, though not necessarily. Then it divides the child support obligation between the two parents. Then it looks at the amount that the non-custodial parent would have to pay and determines whether it should deviate from that amount on the basis that it is unfair.

Let's look at a few examples. In these examples, for purposes of simplicity only, the father is the non-custodial parent and the parents have one child.

Example 1

Father has a "child support income" of $100,000, Mother has $0.

Combined obligation: 17% of $100,000 = $17,000 per year = $1,417 per month.

Since only the father has income, the entire obligation is his. So, the father will pay the mother $1,417 per month.

Example 2

Each parent earns $100,000. (Thus, the combined parental income = $200,000).

Combined obligation: applied to the first $141,000 only, 141,000 x 0.17 = $23,970 = approx. $2,000 per month.

Since the parents incomes are equal, each is responsible for $1,000. Thus, the father would pay the mother $1,000 per month.

But: let's assume the court applies the statute to the full combined income, $200,000. Then the combined obligation is 200,000 x 0.17 = $34,000 per year, one half of which is $17,000, thus the father would pay the mother 1,417 per month, the same as the father in Example #1.

Example 3

Father earns $150,000, Mother earns $100,000 (combined income $250,000.)

Combined obligation (first 141,000): 23,970 = approx 2,000 per month.

The Father's share is 60%, so he would pay the Mother $1,200 per month.

But applying the statute to the full income ($250,000):
Combined obligation would be $42,500 = 3,542 per month.

The Father's share (60%) would be $2,125.