Free spousal support estimate based on Illinois law. Get low, average & high monthly figures — plus duration forecast and factor breakdown.
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Illinois has a statutory maintenance formula under 750 ILCS 5/504. The formula applies when the combined gross income is under $500,000. Amount and duration are both calculated by statute, making Illinois one of the most predictable states for alimony.
Amount: 33.3% of payor net income minus 25% of payee net income. The result cannot cause the payee to receive more than 40% of the combined net income. Duration multipliers: 0.20 for marriages under 5 years, scaling to 1.0 for marriages of 20+ years.
Statutory: multiply years married by a factor — 0.20 for 0-5 years; 0.32 for 5-6 years; increasing to 1.0 for 20+ years which means indefinite.
Pre-set to Illinois — adjust for your situation
Estimates only — not legal advice. Always consult a licensed Illinois family law attorney.
Illinois courts apply state law uniformly across counties. Whether you are in Chicago, Aurora, or Joliet, the calculator above gives you a IL-specific estimate. Select your city below.
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