Illinois Maintenance Calculator
Calculate spousal maintenance using Illinois statutory formula
33.33% of payer's net income minus 25% of payee's net income
33.33% of payer's net income minus 25% of payee's net income
Unlike many states, Illinois has a specific mathematical formula for calculating maintenance amount and duration. The formula is (33.33% x Payer's Net Income) - (25% x Payee's Net Income), subject to a 40% combined income cap.
How Illinois Calculates Maintenance
The Illinois Maintenance Formula
Maintenance = (33.33% x Payer Net) - (25% x Payee Net)
The 40% Cap: The receiving spouse's maintenance plus their net income cannot exceed 40% of the parties' combined net income.
Reference: 750 ILCS 5/504(b-1) - Illinois Marriage and Dissolution of Marriage Act
Calculation Steps
Calculate Net Income
Determine each party's net income after taxes and mandatory deductions
Apply Formula
33.33% of payer's net income minus 25% of payee's net income
Check 40% Cap
Ensure payee's combined income doesn't exceed 40% of combined gross
Determine Duration
Apply the percentage based on marriage length
Illinois-Specific Rules
- Statutory formula: 33.33% payer net - 25% payee net
- 40% combined income cap protects payer
- Duration tied to marriage length with specific percentages
- Marriages 20+ years may receive indefinite maintenance
- Child support calculated before maintenance
- Maintenance is tax-neutral (no deduction/income since 2019)
Calculate Your Illinois Maintenance
Illinois Maintenance Calculator
Enter income information to estimate maintenance
Illinois Maintenance Duration Guidelines
| Marriage Length | Duration Percentage | Example |
|---|---|---|
| 0-5 years | 20% | 5 years = 1 year |
| 5-6 years | 24% | 5.5 years = 1.32 years |
| 6-7 years | 28% | 6.5 years = 1.82 years |
| 7-8 years | 32% | 7.5 years = 2.4 years |
| 8-9 years | 36% | 8.5 years = 3.06 years |
| 9-10 years | 40% | 9.5 years = 3.8 years |
| 10-11 years | 44% | 10.5 years = 4.62 years |
| 15-16 years | 64% | 15.5 years = 9.92 years |
| 20+ years | Indefinite | Court discretion |
For marriages lasting 20 years or more, the court has discretion to order maintenance for an indefinite period. The court may also order maintenance for a fixed term based on the specific circumstances.
Important Legal Disclaimer
This calculator provides estimates based on the Illinois statutory maintenance formula under 750 ILCS 5/504. Actual maintenance awards may differ based on specific circumstances, deviations allowed by law, and judicial discretion. Net income calculations are simplified estimates. Consult with an Illinois family law attorney for advice specific to your situation.
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