Delaware Child Support Calculator

Delaware uses a formula called the Melson formula instead of a support table. The amount depends on both parents’ monthly income before taxes, the number of children, and how many nights the children spend in each home. For one child, with gross incomes of $4,000 and $2,000 a month and the higher earner having fewer than 80 overnights a year, the higher earner pays about $893 a month.

To build the table, we convert weekly pay to monthly pay (× 52 ÷ 12). The 4 nights a month (about 49 a year) are fewer than the 80 a year that lower support, so the amounts are the same as if the children never stayed overnight. When the formula gives less than Delaware’s minimum order, support is $160 for one child or $240 for two or more. Above that, support is limited to half of the paying parent’s income above $1,600.

The formula first sets aside a basic living allowance for each parent, then covers the children’s primary needs, then shares part of what is left with the children. The next section walks through it. The 2026 amounts are in Family Court’s Instructions for Child Support Calculation (Form 509i).

Delaware uses the Melson formula, which works in three steps. First, each parent keeps $1,600 a month to live on. Next, the children’s basic needs are split by each parent’s share of the income left. Last, a standard of living adjustment (SOLA) adds a percentage of whatever income each parent still has, so the children benefit when a parent earns more.

The rules are in Family Court Civil Rules 500 to 510, and the 2026 amounts in Form 509i:

1. Find each parent’s net available income, the income they have left for the children. Start with gross income and subtract allowed deductions (like mandatory pension contributions, union dues, and alimony paid) and the $1,600 each parent keeps to live on (the self-support allowance). If a parent supports other children, 70% of what’s left counts.
2. Find each parent’s share of the combined amount, rounded to a whole percent.
3. Add up primary needs: $800 for the first child in a home and $420 for each additional child, plus work-related child care and 75% of the children’s health insurance premiums.
4. Split primary needs by each parent’s share.
5. Add SOLA: 12% of what each parent has left for one child, 17% for two, 21% for three, and 2% more for each additional child.
6. Subtract what each home already provides and any parenting time adjustment.
7. Apply the 50% limit and the minimum order.

Example

One parent earns $4,000 a month and the other $2,000. After the self-support allowance they have $2,400 and $400, so the higher earner’s share is 86%. They pay 86% of the $800 primary support allowance ($688) plus SOLA of 12% of the $1,712 they have left ($205). With fewer than 80 overnights a year, they pay about $893 a month.

Yes, starting at 80 overnights a year (22%). The paying parent gets a credit at 80 overnights, a bigger one at 125, and from 164 overnights in each home the child counts as living in both. With one child and gross incomes of $4,000 and $2,000 a month, the higher earner pays $893 a month with fewer than 80 overnights, about $789 with 80 to 124, $581 with 125 to 163, and $494 with 164 or more.

With 80 to 124 overnights a year, the paying parent gets a credit of 10% of the other home’s primary support allowance and SOLA; with 125 to 163, the credit is 30%. From 164 overnights in each home (Delaware calls this shared placement), the child counts as half a child in each home. The overnights come from the court order or a written agreement. A parent who says the real number is different needs strong proof (the rule says clear and convincing). See Rule 505(c).

In shared placement no minimum order applies, and no support is ordered when the formula gives less than $50 a month, under Line 24 of Form 509i.

Child care a parent needs to work is added to the children’s primary needs (their basic costs in the formula) and split by each parent’s share of income. The parent who pays the provider gets credit for it.

Only actual costs count; estimated costs aren’t allowed. Private school tuition can also be added in some cases, like a prior agreement or a child’s special needs. See Line 12 of Form 509i and Rule 503.

One or both parents must get health insurance for the children when it’s available through work, reasonable in cost, and usable near where the child lives. The children’s premiums are added to their primary needs, and each parent pays a share of uninsured medical costs.

• Reasonable cost: covering the parent and their children costs no more than 10% of the parent’s gross income, and enough income remains for the children’s primary needs.
• Premiums: 75% of a premium covering the children counts, or 50% if that parent supports other children.
• Uninsured costs: each parent’s share is their income share rounded to a multiple of 10%, in the direction of 50%, and never below 10% or above 90%. Ask for reimbursement by December 31 of the second year after the expense.

See Rule 507 and Lines 12C and 25 of Form 509i.

If the children live with you and you get TANF (Delaware’s cash assistance program), you have to help the Division of Child Support Services get support from the other parent unless you have a good reason, such as a risk of violence. The state keeps most of the support collected, but your family gets the first $50 a month. Food stamps (SNAP) don’t require this.

• TANF: under the Delaware Social Services Manual, you sign your right to support over to the state. If you don’t help without a good reason, your family loses an amount equal to the whole TANF benefit until you do.
• What your family keeps: the first $50 of support collected each month, which doesn’t lower your TANF.
• Food stamps (SNAP): Delaware doesn’t require help with child support for SNAP, according to the USDA SNAP State Options Report.

If helping could put you or your children in danger, ask your benefits worker to excuse you for “good cause.” The Delaware child support guide covers what helping involves.

Each parent keeps $1,600 a month to live on, and support can’t be more than half of the paying parent’s income above that. The minimum order is $160 a month for one child or $240 for two or more when the formula gives a smaller amount. When the paying parent has nothing left above $1,600, the Family Court’s calculator, and ours, show $0, though a judge can base support on what that parent could earn. The minimum doesn’t apply when the children spend at least 164 nights a year in each home, when each parent has at least one of the children living with them, or when the paying parent is disabled.

• Example: a paying parent earning $2,000 a month has $400 above the $1,600, so support for one child is limited to half of that, $200. At $1,600 or less there is nothing left above the allowance, so the Family Court’s calculator, and ours, show $0; a judge can still base support on what the parent could earn.
• Children in three or more homes: the limit is 35% instead of 50%.
• Disability and SSI: a disabled parent with income under $1,600 can be ordered less than the minimum. A parent receiving SSI isn’t ordered to pay unless they have other income or resources.
• Jail or prison: after 180 days in a row, most orders drop to half the minimum ($80 or $120).
• Earning less than they could: support is based on what a parent could reasonably earn. A parent who is out of work by choice, doesn’t document income, or skips the hearing is counted as earning at least $2,390 a month. A parent working under 35 hours a week is counted as working 35.

See Rules 501 and 506 and Form 509i.

No. Delaware has no dollar cap. When a parent has more than $16,000 a month left after the formula’s first steps, 30% of the extra is taken out before the standard of living adjustment, so support grows more slowly at high incomes.

For one child, a paying parent earning $30,000 a month whose child lives with a parent earning $2,000 pays about $3,687 a month. See Rule 504 and Line 16 of Form 509i.

Yes. A judge can order a different amount if the evidence shows the formula amount isn’t in the child’s best interest or is unfair to the parents. If the parents disagree, the order must say why.

Every order, including one the parents agree to, must attach a formula calculation, and the court can reject an agreement that is clearly against the child’s best interest. See Rule 500.

File a Petition for Child Support Modification in Family Court, or ask the Division of Child Support Services (DCSS) to file it if you have a DCSS case. Within 2½ years of your last order, you must show a big change in circumstances and a new amount more than 10% different; after 2½ years, you don’t.

• Through DCSS: if you have a DCSS case, ask DCSS to file the petition for you.
• On your own: file the Petition for Child Support Modification (Form 342) with Family Court.
• Timing: the new amount can start no earlier than 3 days after the summons is mailed, and a formula update alone isn’t a reason to change an order.

The rules are in Rule 508. The Delaware child support guide walks through each step.

Yes. Delaware Family Court publishes its Child Support Calculator as an Excel workbook, with a manual worksheet (Form 509) and instructions (Form 509i). There is no web calculator.

Download it from Family Court’s Child Support Calculator page. It covers deductions, other children, child care, health insurance, and split placement, using the February 2026 amounts.