Estimate monthly support based on the Income Shares Model
1 Child
2 Children
3 Children
4 Children
5+ Children
Calculation Results
Combined Monthly Income:$0.00
Total Support Obligation:$0.00
ESTIMATED MONTHLY PAYMENT BY PARENT 1
$0.00
ESTIMATED MONTHLY PAYMENT BY PARENT 2
$0.00
Understanding Child Support Calculations
Child support is generally calculated using the "Income Shares Model." This model is based on the principle that the child should receive the same proportion of parental income that they would have received if the parents lived together. The calculation looks at the combined net or gross income of both parents and then determines the percentage of that income that would typically be spent on a child.
How the Monthly Amount is Determined
Most jurisdictions use a percentage-based formula that adjusts as the number of children increases. Common baseline percentages include:
1 Child: Approximately 17% of combined income.
2 Children: Approximately 25% of combined income.
3 Children: Approximately 29% of combined income.
4 Children: Approximately 31% of combined income.
5+ Children: Approximately 35% of combined income.
Key Factors in the Calculation
Beyond basic income, several "add-ons" are usually factored into the final support order:
Gross Monthly Income: This includes wages, bonuses, commissions, and sometimes dividends or interest.
Childcare Expenses: Costs for work-related daycare or after-school care are shared proportionally between parents.
Health Insurance: The cost of including the child on a medical, dental, or vision plan.
Parenting Time: In many states, if a parent has the child for more than 128 nights a year, the support amount may be adjusted downward.
Example Calculation
Suppose Parent A earns $4,000/month and Parent B earns $2,000/month. Their combined income is $6,000. For one child (17%), the basic obligation is $1,020. Parent A earns 66.6% of the income, so they would be responsible for $680 per month, while Parent B would be responsible for $340 per month.
Disclaimer: This calculator provides an estimate for educational purposes only. Each state and jurisdiction has specific laws, tables, and deduction rules. Consult with a family law attorney or your local child support agency for a binding calculation.
function calculateSupport() {
var p1Income = parseFloat(document.getElementById("parent1Income").value) || 0;
var p2Income = parseFloat(document.getElementById("parent2Income").value) || 0;
var children = parseInt(document.getElementById("numChildren").value);
var childcare = parseFloat(document.getElementById("childcareCosts").value) || 0;
var insurance = parseFloat(document.getElementById("healthInsurance").value) || 0;
var combinedIncome = p1Income + p2Income;
if (combinedIncome <= 0) {
alert("Please enter income for at least one parent.");
return;
}
// Percentage of income for children (Common Income Shares Model standards)
var rate = 0;
if (children === 1) rate = 0.17;
else if (children === 2) rate = 0.25;
else if (children === 3) rate = 0.29;
else if (children === 4) rate = 0.31;
else rate = 0.35;
// Calculate Basic Obligation
var basicObligation = combinedIncome * rate;
// Add additional costs
var totalObligation = basicObligation + childcare + insurance;
// Determine proportional shares
var p1ShareRatio = p1Income / combinedIncome;
var p2ShareRatio = p2Income / combinedIncome;
var p1Final = totalObligation * p1ShareRatio;
var p2Final = totalObligation * p2ShareRatio;
// Display results
document.getElementById("resCombinedIncome").innerText = "$" + combinedIncome.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalObligation").innerText = "$" + totalObligation.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resP1Payment").innerText = "$" + p1Final.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resP2Payment").innerText = "$" + p2Final.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resultsArea").style.display = "block";
document.getElementById("resultsArea").scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}