DELAWARE SUPPORT GUIDELINE
Delaware child support calculator & worksheet
Delaware uses the Melson Formula on Family Court Form 509. Each parent’s basic needs are protected before remaining income is shared with the children.
Current module status
| State | Delaware |
|---|---|
| Status | Active base worksheet module |
| Guideline model | delaware form 509 monthly formula |
| Primary income field | Monthly net available income |
How Delaware child support law works
Legal starting point. Delaware applies the Melson Formula through Family Court Form 509. The formula is designed to protect each parent’s basic needs before allocating income available for the children, which makes it more detailed than a single income-percentage rule. Read Delaware Family Court Civil Rules 500–510; Form 509.
How the guideline is calculated
Form 509 works through net available income, primary support, a standard-of-living adjustment, and placement credit. Income attribution, household placement, tax treatment, medical support, arrears, and deviations require the actual form and the facts of the case.
What this site’s worksheet covers
Uses Delaware Family Court Form 509 Rev. 2/26 and Form 509i instructions for the 2026 Delaware Child Support Formula, effective February 1, 2026. All amounts are monthly and rounded to whole dollars for Form 509 line calculations before final output. The module calculates Form 509 lines for net available income, primary support, SOLA, parenting-time credit, self-support protection, minimum order and cash medical support. Reasonable earning capacity, undocumented income, disability, incarceration, tax treatment, private school equities, insurance affordability, reimbursement petitions, arrears repayment and deviations require court-specific review. Shared/split placement requires exact household placement and overnights; this module accepts children in each home but flags those cases for review.
Documents that make the worksheet more useful
Form 509 and Form 509i: primary support, SOLA, tax adjustments, and placement. Gather the records that support the income, parenting-time, insurance, child-care, and other adjustment entries that apply to the family. Line 3: the 7% deduction applies to documented self-employment earnings within the combined wage/self-employment earnings ceiling. SSA income is excluded from the Line 2 nontaxable surcharge. Documentary eligibility remains a user-supplied determination.
For a filing or agreement, complete the official court forms linked on this page. They use the same guideline structure explained here, and the court applies it to the facts of the case.
Before you enter your numbers
What does Delaware's SOLA add to primary support?
The Melson Formula first protects parental self-support and allocates the children's primary needs. Its standard-of-living adjustment then assigns children a share of income left after those steps. SOLA is consequently a second calculation, not another name for the initial basic-support amount.
Prepare this: Use Form 509 with its instructions. Keep the primary-needs entries, each parent's available income, and placement credits distinct so no expense or credit is counted twice.
Read the relevant official instructions: Delaware Family Court Civil Rules 500–510; Form 509.
These preparation notes explain one part of the state guideline. A new estimate does not change an existing order; a modification request does.
How Delaware cases actually get to a number
Form 509 is not a combined-income table. It walks through net available income, primary support, a standard-of-living adjustment, and placement credit. Skipping to a ‘percentage of pay’ estimate discards the formula’s structure.
Delaware uses the Melson Formula on Family Court Form 509. Each parent’s basic needs are protected before remaining income is shared with the children. That is a different path from neighboring states that use another model, so do not import a table, percentage, or overnight credit from somewhere else.
Parenting time in Delaware
Placement credit is built into Form 509. Which household is the primary residence, and how much time the children spend in each home, changes the credit. Labeling a plan ‘shared’ without matching the form’s definitions will misstate support.
Costs Delaware usually treats separately
- Child-care necessary for work
- Health insurance for the children
- Extraordinary medical expenses
- Other Form 509 add-ons the court includes
When Delaware courts leave the guideline
The Melson result is the guideline. Deviations still require findings. Self-employed income, imputed income, and tax filing status are common reasons two Form 509s disagree.
Official Delaware forms to keep beside this guide
Form 509 and Form 509i: primary support, SOLA, tax adjustments, and placement. Line 3: the 7% deduction applies to documented self-employment earnings within the combined wage/self-employment earnings ceiling. SSA income is excluded from the Line 2 nontaxable surcharge. Documentary eligibility remains a user-supplied determination. The primary authority is the published Delaware source. Fill the official form from source documents. Use this page only to check that you chose the right Delaware path—primary versus shared, table versus percentage, add-ons versus basic support.
Where this is typically filed
Family Court of Delaware hears these cases. Bring the current Form 509 instructions. Older Melson spreadsheets may not match the present personal-allowance figures.
Questions specific to Delaware
Is Delaware an income-shares table state?
No. Delaware uses the Melson Formula, which protects each parent’s primary needs before allocating remaining income.
Why does the personal allowance matter so much?
Primary support is calculated after each parent’s self-support needs. That step does not exist in a simple percentage model.
Can I ignore taxes on Form 509?
No. Net available income depends on the form’s tax treatment. Paystub net is not a substitute.
Run the calculator
Open the free support calculator, select Delaware, complete the state worksheet, and print or export the output for review.