Child Support Percentage Calculator: Annual Obligation From Income
Estimate a child support obligation from net income and a state guideline percentage — a quick figure for budgeting, not a legal calculation.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Annual child support | Income net of support |
|---|---|---|
| 17% of $60,000 (NY 1 child) | 10,200 | 49,800 |
| 25% of $80,000 (NY 2 children) | 20,000 | 60,000 |
| 29% of $120,000 (NY 3 children) | 34,800 | 85,200 |
| 20% of $45,000 | 9,000 | 36,000 |
How This Calculator Works
Enter annual net income and the state guideline percentage (NY: 17% for one child, 25% for two, etc.). The calculator multiplies the two to give the annual support amount and shows what's left of net income.
The Formula
Percentage of an Amount
Amount is the base value, Percentage is the rate applied to it
Worked Example
On $60,000 net income with a 17% NY one-child guideline, child support is $10,200 a year — about $850 a month. The figure leaves $49,800 of net income before any other obligations. Actual orders almost always differ from this simple estimate because most state formulas factor in parenting time, healthcare, child care, and the other parent's income.
Key Insight
This calculator gives a back-of-envelope figure. Real child support orders are calculated by state-specific worksheets that account for the income-shares model (combining both parents' incomes), parenting-time adjustments, healthcare and child care costs split, and special needs. Family-law attorneys and state-specific online calculators give legally meaningful estimates; this one gives the rough order of magnitude for planning.
Frequently Asked Questions
How is child support calculated?
Varies by state. Some states (NY, IL, ND) use simple percentage of obligor's income. Most others use income-shares model (both parents' incomes combined, then split by parenting time). The flat-percentage approach here is the simpler version.
What is a typical guideline percentage?
Percentage-of-income states: 1 child often 17% to 22%, 2 children 25% to 30%, 3 children 29% to 35%, 4 children 31% to 39%, 5+ children 35%+. Income-shares states use different math entirely.
Does parenting time affect it?
In most states yes — substantially. Equal-parenting-time arrangements often produce very different support amounts than primary-custodian arrangements. This simple calculator ignores parenting time; real orders don't.
Is child support tax-deductible?
No — child support is not tax-deductible by the payor and is not taxable to the recipient under US federal law (since 2019). Alimony has different and changing tax treatment.
Can the amount be modified?
Yes — child support orders can be modified when circumstances materially change (job loss, large income increase, custody change, child's needs). Modifications require a court order; informal changes are not legally enforceable.
Related Calculators
Methodology & Review
Child support is net income multiplied by the applicable state guideline percentage. The calculator models a single flat rate; most state formulas blend multiple factors (income shares model, parenting time adjustments, healthcare and child care credits) that need a state-specific calculator for a true legal estimate. Use this as a quick order-of-magnitude figure only.
Written by Ugo Candido · Last updated May 17, 2026.