New Jersey uses a formula, not a fixed amount, so what you pay or receive depends on both parents' income

New Jersey does not have a single child support number. Instead, the state uses the Child Support Guidelines, a formula that takes both parents' gross income, the number of children, and custody time into account. The formula produces a monthly obligation that can range from under $100 to over $2,000 per month depending on the parents' earnings and how much time each parent spends with the children.

The formula applies to most cases, though a judge can order a different amount if the standard calculation would be unfair given the family's specific circumstances — for instance, if one parent has very high income, significant debt, or unusual expenses. Understanding how the formula works helps you predict what a court might order, or what you might owe if you and the other parent reach an agreement outside court.

Key Takeaways

  • New Jersey's formula starts with both parents' gross income and applies a percentage that decreases as income rises and as the number of children increases.
  • The formula produces a base amount, then adds costs for childcare, health insurance, and unreimbursed medical expenses, split between parents according to their income share.
  • Custody time matters: the parent with the children more than 50 percent of the time usually receives support, and the formula adjusts if both parents share time roughly equally.
  • Income includes salary, wages, bonuses, self-employment earnings, rental income, and some benefits; it does not include child support or spousal support received from someone else.
  • A judge can order an amount different from the formula if applying it would be unjust or inappropriate, but the judge must explain in writing why the formula does not work.

How the base child support amount is calculated

The formula begins with combined parental income — both parents' gross income added together. Gross income means income before taxes and includes W-2 wages, self-employment earnings, bonuses, commissions, rental income, investment income, and certain benefits. It does not include child support or spousal support the parent receives from a previous relationship.

Once combined income is determined, New Jersey applies a percentage based on how many children need support. The percentages are: 17 percent for one child, 25 percent for two children, 29 percent for three children, 31 percent for four children, and 35 percent for five or more children. These percentages apply only to combined income up to a cap, which changes each year. For 2024, the cap is $163,000 combined income; amounts above that are handled separately.

The result is the base child support obligation. Then each parent's share is calculated by dividing their individual income by the combined income. For example, if combined income is $100,000 and the obligation for two children is $25,000 per year, and one parent earns $60,000 while the other earns $40,000, the higher-earning parent pays 60 percent of $25,000, or $15,000 per year ($1,250 per month).

Add-ons for childcare, health insurance, and medical costs

The base amount is not the final number. New Jersey requires both parents to split the cost of childcare needed for work or school, health insurance premiums for the children, and unreimbursed medical, dental, and orthodontic expenses. These are calculated separately and added to the base obligation.

Childcare costs are split in the same proportion as the base obligation — if one parent pays 60 percent of base support, they pay 60 percent of childcare too. Health insurance premiums for the children are also split by income share. Unreimbursed medical expenses — copays, deductibles, therapy, prescriptions not covered by insurance — are split the same way once they exceed $250 per year per parent.

If one parent already carries the health insurance, that parent may receive credit for the premium they pay, reducing what they owe in cash support. The other parent then reimburses their share of the premium directly to the parent who carries the policy, or the court may order it deducted from the support payment.

How custody time changes the calculation

If one parent has the children more than 50 percent of the time, that parent receives support from the other parent. If both parents share custody roughly equally — each having the children 40 to 50 percent of the time — the formula adjusts. The parent with higher income still pays, but the amount is reduced because the lower-income parent is also covering the children's expenses during their time.

Custody time is measured in overnights per year. A parent with 183 or more overnights is considered to have the children more than 50 percent of the time. If both parents have between 128 and 217 overnights (roughly 35 to 60 percent), the court may apply an adjusted formula. The exact adjustment depends on how close the split is to 50-50.

If one parent has very little time — fewer than 128 overnights per year — the standard formula applies without adjustment, and the other parent receives the full calculated amount.

Income above the cap and high-income cases

The percentages (17 percent, 25 percent, etc.) apply only to combined income up to the cap. For 2024, that cap is $163,000. If combined income exceeds the cap, the amount above it is treated separately. The court has discretion to apply the same percentage to income above the cap, apply a lower percentage, or order no support on the excess income.

In practice, courts often apply a lower percentage to high income — sometimes 5 to 10 percent instead of 25 percent — to avoid creating a support obligation that exceeds what the children actually need. A judge must consider the children's standard of living, the parents' ability to pay, and other factors when deciding how to handle income above the cap.

If one parent is self-employed or has irregular income, the court may average income over several years or use a recent year's tax return as the basis, depending on whether the income is genuinely variable or the parent is underreporting.

When a judge can order a different amount

The formula is the starting point, not the final answer. A judge can order support that differs from the formula if applying it would be unjust or inappropriate. Reasons include: one parent has very high income and the formula would create an unreasonably large obligation; one parent has significant debt or financial obligations unrelated to the children; one parent is disabled or unable to work; the children have special needs requiring extra expenses; or one parent is providing substantial in-kind support (like housing the children rent-free).

When a judge deviates from the formula, they must write an explanation stating which factor or factors justified the change and how the new amount was calculated. This explanation becomes part of the court order and can be reviewed if either parent later asks the court to modify support.

How to find out what you might owe or receive

If you are in a child support case, the court will calculate the amount using the formula and include it in the order. If you want to estimate what the formula would produce before going to court, you can gather the following information: both parents' gross income for the most recent year (from tax returns or pay stubs), the number of children, the expected custody arrangement in overnights per year, and the cost of childcare and health insurance for the children.

New Jersey's Judiciary website provides a Child Support Guidelines calculator that applies the formula. It is a tool for estimation only — the actual court order may differ based on the judge's findings and any adjustments for high income or other factors. If you are working with a family law attorney, they can run the calculation and explain what the formula produces in your situation.

If you and the other parent reach an agreement outside court, you can agree to any amount you both accept, even if it differs from the formula. However, the court must still review the agreement to ensure it is not unconscionable — meaning shockingly unfair — before it becomes an enforceable order.

Frequently Asked Questions

Does New Jersey count child support I receive from a previous relationship as income?

No. Child support you receive from another parent is not counted as income for the formula. Spousal support (alimony) you receive is also excluded. However, income you earn from work, investments, or self-employment is counted, even if you use that income to pay support to someone else.

What if one parent does not have a job or reports very low income?

The court can impute income — assign an income level based on the parent's earning capacity rather than what they actually report. If a parent is unemployed or underemployed, the court may use minimum wage, the state average wage for their age and education, or their prior earnings history. The parent can argue they are genuinely unable to work, but they must provide evidence.

Can child support be modified if income changes?

Yes. Either parent can ask the court to modify support if there has been a substantial change in circumstances — usually a 10 percent or more change in either parent's income, a significant change in custody time, or a major change in childcare or health insurance costs. The request goes back to the court, and the judge recalculates using current income.

Does New Jersey child support cover college expenses?

The formula covers support through age 19 or high school graduation, whichever comes later. College support is separate and is not automatic. A parent can ask the court to order college support, but the court has discretion and considers factors like the parents' income, the child's academic performance, and the parents' prior agreement about education.

What happens if the paying parent loses their job?

Support does not automatically stop. The paying parent must ask the court for a modification, providing evidence of job loss and current income (or lack of it). If the parent is receiving unemployment benefits, those count as income. The court will not reduce or eliminate support simply because a parent chose to leave a job, but genuine job loss or a significant income drop can result in a lower obligation.