Illinois Maintenance Calculator
Estimate maintenance (alimony / spousal support) for Illinois based on income, marriage length, and state guidelines. This is a starting point, not legal advice — every case is different.
How is maintenance calculated in Illinois?
Formula: 33.3% of higher income minus 25% of lower income. Capped so recipient gets no more than 40% of combined income. Under current law, Illinois is an equitable distribution state, meaning marital assets are generally divided fairly but not necessarily equally.
Maintenance (also called alimony, spousal support, spousal maintenance) in Illinois is typically based on factors including: the length of the marriage, each spouse's income and earning potential, the standard of living established during the marriage, age and health of both parties, and each spouse's financial needs and obligations.
Illinois Maintenance formula
Amount: (33.33% × payor's gross income) − (25% × payee's gross income)
Cap: The recipient cannot receive more than 40% of the combined gross income of both parties.
Duration: Multiplier starts at 0.20 for marriages under 5 years, increasing by 0.04 per year bracket up to 0.80 for 19–20 year marriages. Marriages of 20+ years may result in indefinite maintenance.
Source: 750 ILCS 5/504(b-1)(1.5)
How long does maintenance last in Illinois?
Duration is typically tied to the length of the marriage. A common rule of thumb is that maintenance lasts for about one-third to one-half the length of the marriage. The actual duration in Illinois depends on the specific circumstances of your case and judicial discretion.
Maintenance usually ends when the recipient remarries, either spouse dies, or the court determines the recipient has had enough time to become self-supporting.
Related resources
From uncertainty to clarity in 3 steps
No account required. No credit card. Just your numbers.
Enter your numbers
Settlement amount, income, expenses, alimony, house — takes about 2 minutes. Everything runs privately in your browser.
See the projection
Get a year-by-year chart showing your net worth from now through age 100. Green, yellow, or red — you'll know where you stand instantly.
Model & export
Test different settlement terms to find which saves you the most money, compare offers side-by-side, and export a report for your attorney.
Every projection is deterministic — same inputs always produce the same outputs. Results are estimates based on the assumptions you provide.
See what a Pro analysis looks like
We built a complete Pro analysis for a fictional person named Sarah. Explore every section — charts, what-if scenarios, risk timeline, negotiation leverage — so you can see what’s included before running your own numbers.
You don’t need a $5,000 CDFA retainer to understand your own numbers
Start with the free projection. If the numbers raise questions you can’t answer, upgrade to Pro for $19 — one-time, no subscription — and discover which settlement terms could save you thousands.
Not financial or legal advice. DivorceSmart is an educational planning tool. Always consult a qualified attorney and financial advisor before making settlement decisions.