Child Support Arrears and Interest Calculator
Calculate the total amount owed in child support arrears, including accrued interest, based on missed payments and your state's interest rate.
Common rates: CA=10%, TX=6%, FL=12%, NY=9%. Check your state's law.
Formulas Used
Principal Arrears:
Net Principal = (Monthly Order × Months Missed) − Payments Already Made
Simple Interest (most states):
I = P × r × (t / 12)
where P = net principal, r = annual interest rate (decimal), t = months accruing
Compound Interest (monthly, some states):
I = P × [(1 + r/12)t − 1]
Total Owed = Net Principal + Accrued Interest
Assumptions & References
- Interest begins accruing from the date each payment was due and missed (simplified here as a lump-sum principal).
- Most U.S. states apply simple interest on child support arrears; a minority use compound interest.
- Common statutory interest rates: California 10% (Fam. Code §17433.5), Texas 6% (Fam. Code §157.265), Florida 12% (§55.03 F.S.), New York 9% (CPLR §5004).
- This calculator does not account for cost-of-living adjustments (COLAs), modification orders, or lump-sum payments applied mid-period.
- Consult a family law attorney or your state's child support enforcement agency (Title IV-D) for an official arrears determination.
- Federal law (42 U.S.C. §666) requires states to have procedures for collecting arrears; enforcement tools include wage garnishment, tax refund intercept, and license suspension.