Illinois Alimony Calculator
Estimate Illinois guideline maintenance from both spouses' net incomes and years married — amount uses the statutory 33⅓% / 25% formula with the 40% combined-net cap; duration uses the guideline multipliers. Click any i for detail.
Illinois guideline inputs
Income figures are
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Income basis
Guideline math is defined on net income. If you enter gross, treat the result as a rougher first pass. |
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Payor net income ($)
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Payor net income
Paying spouse's net income after allowed deductions — the statute's starting point for guideline maintenance. |
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Recipient net income ($)
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Recipient net income
Receiving spouse's net income. Higher recipient income lowers guideline maintenance. |
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Marriage length (years)
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Marriage length
Used for the statutory duration multiplier table (e.g. 10–11 years → 44% of marriage length). |
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Combined gross income ($/yr)
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Combined gross
Guideline amount rules generally apply when combined gross is under $500,000 (and other conditions). We flag when you're at or above that threshold. |
How to use this calculator
- Set incomes to annual or monthly net (same basis for both).
- Enter payor and recipient net income.
- Enter marriage length in years for the duration multiplier.
- Enter combined gross to see whether the $500k guideline threshold may block pure guideline use.
Results explained
Illinois guideline maintenance is roughly 33⅓% of payor net minus 25% of recipient net, then capped so the recipient's net plus maintenance does not exceed 40% of combined net. Duration multiplies marriage length by a statutory factor that rises with years married; at 20+ years the court may order a term equal to the marriage or indefinite maintenance.
Quick reference: Illinois guideline
Educational model of 750 ILCS 5/504 — confirm current statute and case facts with counsel.
| Item | Detail |
|---|---|
| Amount | 33⅓% × payor net − 25% × payee net |
| Cap | Payee net + maintenance ≤ 40% combined net |
| Duration (example) | 10–11 yrs marriage → ×0.44 |
| Guideline gate | Often combined gross < $500,000 |
For house equity in a divorce, see the divorce buyout calculator.
How the estimate is built
Annual maintenance = max(0, min(raw, cap)) where raw = payor_net/3 − 0.25×payee_net and cap = 0.4×(payor_net+payee_net) − payee_net. Monthly = annual ÷ 12. Duration years ≈ marriage_years × multiplier(marriage_years).
Example scenario
Payor net $110,000 and payee net $38,000 → raw = $36,663 − $9,500 = $27,163/year. Combined net $148,000; 40% = $59,200; cap = $59,200 − $38,000 = $21,200/year — so the cap binds (~$1,767/month). A 10-year marriage uses a 0.44 multiplier → about 4.4 years of guideline duration.
FAQ
When do guidelines not apply?
Commonly when combined gross income is $500,000 or more, or the payor already owes child support/maintenance from a prior relationship — then courts use non-guideline factors. This page still shows the formula for illustration and warns on the gross threshold.
Gross vs net?
The statute's guideline arithmetic is on net income. Gross is only used here for the $500k combined-gross gate.
Is maintenance taxable?
Tax treatment depends on the agreement or order and federal/state rules for your years. Ask a tax professional; we do not model taxes.
Can we agree to something else?
Yes — parties often settle above or below guidelines. Courts can also find guideline application inappropriate in a given case.