Income Shares Model
Used by ~40 states. Both parents' incomes are combined to find total "available income for the child." The guideline table sets a base support amount. Each parent contributes proportionally based on their share of combined income. The non-custodial parent pays their proportion to the custodial parent.
Percentage of Income Model
Used by Texas, Wisconsin, and several other states. Only the paying parent's income matters. Support is a fixed percentage: 1 child = 20%, 2 children = 25%, 3 = 30%, 4 = 35%, 5+ = 40% of net income.
Texas Percentage Guidelines
| Children | % of Net Income |
|---|---|
| 1 | 20% |
| 2 | 25% |
| 3 | 30% |
| 4 | 35% |
| 5+ | 40% |
Disclaimer: This is an educational estimate only. Courts apply state-specific worksheets, local rules, and judicial discretion. Consult a licensed family law attorney in your state for accurate guidance.
U.S. Child Support in Numbers
The U.S. Census 2021 Child Support Report found 13.6 million custodial parents in the U.S., 49.4% of whom had a formal child-support agreement. Total support owed was $32.3 billion; $25.1 billion (77.7%) was actually received. Median annual amount received was $3,500 — $292/month — far below what guideline calculators typically produce, reflecting the gap between orders and collection.
Every state uses one of three models: Income Shares (41 states, including CA/NY/TX/FL), Percentage of Income (6 states including Alaska, Illinois, Wisconsin), or Melson (3 states: Delaware, Hawaii, Montana). The Income Shares model combines both parents' income, pro-rates support obligation, and assigns each parent a share — Texas uses straight percentage: 20% of net income for one child, 25% for two, rising to 40% for six+.
Collection rates vary widely by state. The OCSE 2022 Federal Preliminary Data Report shows collection rates ranging from 44% (Alabama, Nevada) to 85%+ (Pennsylvania, South Dakota) — a 40 percentage point spread. Wage withholding accounts for 75% of all collections nationally. Back-support (arrears) totaled $113.7 billion across active cases in 2022, most of which is uncollectable due to incarceration, unemployment, or deceased obligors.
Sources: Census 2021 Child Support Report, OCSE Preliminary Data Report 2022, state statutory formulas
Methodology & Assumptions
This calculator implements standard formulas drawn from primary-source authorities. Values are point-in-time estimates; consult a licensed professional for high-stakes decisions. See the per-input definitions and source citations below.
How this works
Computations are deterministic and run client-side — no inputs leave your
browser. Formulas are derived from
standard published formulas for the calculator's domain (mortgage,
taxes, energy, conversions, etc.). When the underlying agency publishes
updated rates or thresholds we refresh defaults and update the page's
lastmod timestamp.
| Input | Default | Source / authority |
|---|---|---|
| All inputs | Domain-typical defaults | Editorial methodology, CalcMesh 2026 |