Delaware Child Support Calculator

Delaware calculates child support with the Melson Formula, set out in Family Court Civil Rules 500 to 510. Each parent keeps a $1,600 self-support allowance, the children’s primary needs are split by income, and a standard of living adjustment (SOLA) shares 12% or more of each parent’s remaining income with the children. The current version took effect February 1, 2026. The calculator below follows the 2026 worksheet (Form 509), including the parenting time credit and shared placement.

Deduct mandatory pension contributions, union dues, disability insurance, health insurance not covering these children and alimony paid. Do not deduct income taxes (Form 509 Lines 1–4).
80–124 overnights earns a 10% credit, 125–163 a 30% credit; 164 or more for each parent is shared placement.
Add-on costs (monthly, optional)
Compare your order with what the guideline produces today.

How the Melson Formula works

The Melson Formula, named for the Family Court judge who developed it, is a rebuttable presumption: the court uses its result unless it finds that result contrary to the child’s best interest or unfair, and must state on the record why. It works in three layers.

  1. Net income available. Start with each parent’s monthly gross income. Subtract allowable deductions: mandatory pension contributions (and voluntary retirement contributions up to the 5% limit), union dues, disability insurance, health insurance that does not cover the children in the case, and court-ordered alimony paid. Then subtract the $1,600 self-support allowance. A parent who supports other children in their home keeps only 70% of the remainder for this case.
  2. Primary support. The children’s basic need is the primary support allowance, $800 for one child plus $420 for each additional child, plus work-related child care, approved private school costs and 75% of health insurance premiums for the children (50% if the parent has other children). Each parent owes their percentage share of that total.
  3. Standard of living adjustment. After primary support, each parent’s leftover income is multiplied by the SOLA percentage: 12% for one child, 17% for two, 21% for three and 2% more for each additional child. When a parent’s leftover income exceeds $16,000 a month, a high-income offset reduces the SOLA base.

The parent the children live with is credited for the primary support allowance and SOLA they provide in their home, and each parent is credited for child care and insurance they pay directly. What remains for the other parent is the net monthly obligation.

Example: gross incomes of $5,000 and $3,000 a month, one child living with the lower earner, and no child care or insurance. After the self-support allowance, the parents have $3,400 and $1,400 available, so the higher earner’s share is 71%. That parent owes $567 in primary support plus $340 in SOLA, about $907 a month.

Parenting time and shared placement

A paying parent with regular overnights keeps part of the other home’s primary support and SOLA:

  • 79 or fewer overnights a year: no adjustment.
  • 80 to 124 overnights: 10% credit.
  • 125 to 163 overnights: 30% credit.
  • 164 or more for each parent: shared placement. Each child is counted as half a child in each home, both parents’ obligations are calculated and offset, and no support is assessed if the difference is under $50 a month.

The count comes from the current custody order or agreement. A parent who claims a different practice must prove it by clear and convincing evidence.

Limits and minimums

  • Self-support protection. A parent’s obligation cannot exceed 50% of their net available income (35% if the parent supports children in three or more households).
  • Minimum orders. Outside shared or split placement, and unless the paying parent is disabled, the minimum order is $160 a month for one child and $240 for two or more.
  • Imputed income. Support is based on reasonable earning capacity. A parent who is unemployed or underemployed without good reason can be imputed at least the presumptive minimum income of $2,390 a month.
  • Uninsured medical costs. These are split using each parent’s share of net income, rounded toward 50% to the nearest 10%.

Changing an existing Delaware order

Within 2½ years of the last support order, a petition to modify must allege with particularity a substantial change of circumstances that the petitioner did not cause by voluntary or wrongful conduct, and the order will not be changed unless the formula shows a change of more than 10%. After 2½ years, neither the particularity nor the 10% requirement applies. A change in the formula itself is not a ground for modification. A modification can reach back no further than three days after the summons is mailed, so filing promptly matters. The new order can raise, lower or reverse support no matter which parent filed.

Enter your current order in the calculator to see the gap. Our free modification audit walks through the rest, and the 50-state book covers the Delaware filing process step by step.

Delaware child support FAQ

Does Delaware use gross or net income for child support?

Gross. Since 2018, income taxes are no longer deducted; the worksheet starts with gross income, then subtracts specific deductions and the $1,600 self-support allowance.

What is the minimum child support in Delaware?

$160 a month for one child and $240 for two or more, unless the children are in shared or split placement or the paying parent is disabled.

How many overnights reduce child support in Delaware?

80 to 124 overnights earns a 10% parenting time credit, 125 to 163 earns 30%, and 164 or more for each parent is treated as shared placement.

When can I modify child support in Delaware?

Any time after 2½ years from the last order. Before that, you must show a substantial change with particularity and a change of more than 10%.

Sources

This page and calculator provide general legal information, not legal advice. Child support rules change and the court decides the final amount. For advice about your situation, consult a licensed Delaware attorney.