Calculation is client-side, income figures are never transmitted or stored.
How Delaware Child Support Is Calculated
- Delaware uses the Melson Formula -- one of only 3 states (with Hawaii and Montana) that use this three-step model instead of income shares or a flat percentage.
- Step 1: Each parent keeps a Self-Support Allowance ($1,600/month as of 2026, 120% of the one-person federal poverty guideline) before anything else is counted -- this comes off gross income first.
- Step 2: The children's Primary Support need (a per-child allowance of $420 plus a per-household allowance of $380, plus childcare and health insurance) is prorated between the parents by their share of remaining income (Net Available Income, NAI).
- Step 3: The Standard of Living Adjustment (SOLA) shares each parent's LEFTOVER income (after their own primary share) with the children, at a percentage that rises with the number of children (12% for one, 17% for two, 21% for three, +2% each additional) -- simulating what the children would enjoy if the family lived together.
- A High Income Offset reduces the SOLA base by 30% of any combined income above 10 times the Self-Support Allowance ($16,000/month combined).
- A parenting-time credit (10% at 80-124 overnights/year, 30% at 125-163) reduces the paying parent's obligation, and a Self-Support Protection caps the obligation at 50% of that parent's own Net Available Income.
- A minimum order applies: $160/month for one child, $240/month for two or more.
Delaware Child Support Worksheet Walkthrough
Example: Parent A earns $5,000/mo, Parent B earns $3,000/mo, 2 children, Parent B is the noncustodial parent with 0 overnights.
- Net Available Income: Parent A = $5,000 - $1,600 = $3,400. Parent B = $3,000 - $1,600 = $1,400. Combined = $4,800.
- Primary Support Need: 2 × $420 + $380 = $1,220. Parent B's share (1,400/4,800 = 29.2%): $356.
- Parent B's NAI for SOLA: $1,400 - $356 = $1,044. Combined NAI for SOLA ($3,580) × 17% SOLA rate = $609 total, Parent B's 29.2% share ≈ $178.
- Parent B's total obligation: $356 (primary) + $178 (SOLA) ≈ $533/month.
How This Calculator Works — Formula & Constants
Source: The Family Court of the State of Delaware (Form 509, Rules 500-509) · Calcul déterministe — no AI, no arbitrary estimate.
Constants used
| Constant | Value | Source |
|---|---|---|
| Self-Support Allowance | $1,600/mo | Del. Fam. Ct. Civ. P. R. 500-509 |
| Primary allowance, per child | $420 | Del. Fam. Ct. Civ. P. R. 500-509 |
| Primary allowance, per household | $380 | Del. Fam. Ct. Civ. P. R. 500-509 |
| SOLA %, 1/2/3 children | 12% / 17% / 21%, +2% each additional | Del. Fam. Ct. Civ. P. R. 500-509 |
| High Income Offset threshold | 10× Self-Support Allowance | Del. Fam. Ct. Civ. P. R. 500-509 |
| Self-Support Protection | 50% of paying parent's Net Available Income | Del. Fam. Ct. Civ. P. R. 500-509 |
Formula (the Melson Formula)
share(parent) = NAI(parent) / combined NAI
Primary Need = children × per-child allowance + per-household allowance + childcare + health insurance
Primary Obligation(parent) = share(parent) × Primary Need
NAI for SOLA(parent) = NAI(parent) - Primary Obligation(parent)
High Income Offset = 30% × combined excess above 10× Self-Support Allowance
SOLA = (combined NAI for SOLA - High Income Offset) × SOLA%
support = paying parent's (Primary Obligation + share of SOLA)
Deterministic calculation based on Delaware's Melson Formula. Verify against Delaware's official calculator for a court-ready figure.
FAQ
How is child support calculated in Delaware?
Delaware uses the Melson Formula -- one of only 3 states (with Hawaii and Montana) that use this three-step model instead of income shares or a flat percentage. Step 1: Each parent keeps a Self-Support Allowance ($1,600/month as of 2026, 120% of the one-person federal poverty guideline) before anything else is counted -- this comes off gross income first. Step 2: The children's Primary Support need (a per-child allowance of $420 plus a per-household allowance of $380, plus childcare and health insurance) is prorated between the parents by their share of remaining income (Net Available Income, NAI). Step 3: The Standard of Living Adjustment (SOLA) shares each parent's LEFTOVER income (after their own primary share) with the children, at a percentage that rises with the number of children (12% for one, 17% for two, 21% for three, +2% each additional) -- simulating what the children would enjoy if the family lived together. A High Income Offset reduces the SOLA base by 30% of any combined income above 10 times the Self-Support Allowance ($16,000/month combined). A parenting-time credit (10% at 80-124 overnights/year, 30% at 125-163) reduces the paying parent's obligation, and a Self-Support Protection caps the obligation at 50% of that parent's own Net Available Income. A minimum order applies: $160/month for one child, $240/month for two or more.
What is the Melson Formula, and why does only Delaware use it (with Hawaii and Montana)?
The Melson Formula is a three-step child support model, named after a Delaware Family Court judge, that first guarantees each parent a Self-Support Allowance before anything else counts, then prorates the children's basic Primary Support need, and finally shares each parent's LEFTOVER income with the children through a Standard of Living Adjustment (SOLA). Only Delaware, Hawaii, and Montana use this model -- most other states use income shares (combining both parents' income and looking up a table) or a flat percentage of the paying parent's income.
What is Delaware's Standard of Living Adjustment (SOLA)?
After each parent's Self-Support Allowance and share of the children's Primary Support need are set aside, the SOLA shares a percentage of what's LEFT OVER with the children -- 12% for one child, 17% for two, 21% for three, plus 2% for each additional child. This simulates the standard of living children would have enjoyed if their parents lived together, rather than just covering basic needs. A High Income Offset reduces this at very high incomes (above 10 times the Self-Support Allowance).
Is there a minimum child support order in Delaware?
Yes -- $160/month for one child, $240/month for two or more, regardless of how the Melson Formula calculation comes out, unless the court finds a documented reason to deviate (such as a genuinely unable-to-pay circumstance under the Low-Income Adjustment).
Methodology & Source
Formula model: melson. Effective 2026-02-01, guideline version 2026-DE-v1, last reviewed 2026-07-13.
Official source: The Family Court of the State of Delaware (Form 509, Rules 500-509) (Del. Fam. Ct. Civ. P. R. 500-509).
This calculator approximates Delaware's Melson Formula: no adjustment for a parent's other dependent children (Rule 502(e), 70% multiplier), no private-school primary expense (Rule 503(c)), and health insurance/childcare are added as flat combined figures rather than the worksheet's exact 3/4-vs-1/2 premium-sharing split (Rule 503(b)(3)). Shared Equal Placement (164+ overnights each) and the Low-Income Adjustment (Rule 506) are not modeled.
Guideline figures transcribed from the primary source above and cross-checked against Delaware's official calculator/worksheet for multiple test scenarios — see our verification methodology.