Illinois Alimony Calculator
Estimate spousal support (alimony) in Illinois. Understand the types of alimony available, how courts calculate amounts, and how long payments may last. Updated for 2026.
Illinois has a statutory guideline formula under 750 ILCS 5/504(b-1). Applies when combined gross annual income is less than $500,000 and payor has no prior support obligations. Amount: (33.33% × Payor's Net Income) minus (25% × Payee's Net Income). Cap: payee's maintenance cannot result in receiving more than 40% of combined net income. Duration: length of marriage multiplied by a statutory multiplier ranging from 0.20 (under 5 years) to 0.80 (19-20 years). Marriages of 20+ years: court discretion for duration equal to marriage length or indefinite.
Estimate Your Alimony
Interactive Calculator Coming Soon
Our Illinois alimony estimator will help you understand potential spousal support amounts based on your income, marriage length, and other factors. Sign up to be notified when it launches.
Get Started with Divorce.aiTypes of Alimony in Illinois
Fixed-term (Guideline)
Set amount for a set duration per the statutory formula. Duration is calculated by multiplying the length of the marriage by the applicable multiplier from the duration table. Terminates automatically at expiration.
Reviewable
Court sets an initial amount and duration but reviews at a future date. Required for marriages of 10+ years unless parties agree otherwise.
Indefinite/Permanent
Available for marriages of 20+ years at court discretion. Duration may equal the length of the marriage or be indefinite.
Temporary
Awarded during the pendency of the divorce proceedings. Ends when the final judgment is entered.
Understand your alimony options
Divorce.ai helps you evaluate whether alimony is likely in your Illinois divorce and plan accordingly.
Factors Illinois Courts Consider
When determining whether to award alimony and how much, Illinois courts evaluate:
Income and property of each party, including marital property apportioned and non-marital property assigned (504(a)(1))
Needs of each party (504(a)(2))
Realistic present and future earning capacity of each party (504(a)(3))
Any impairment of earning capacity due to devoting time to domestic duties or foregoing education/training (504(a)(4))
Any impairment of earning capacity due to time needed to acquire education/training to become self-supporting (504(a)(5))
Time necessary for the party seeking maintenance to acquire appropriate employment (504(a)(6))
Standard of living established during the marriage (504(a)(7))
Duration of the marriage (504(a)(8))
Age, physical, and emotional condition of both parties (504(a)(9))
Tax consequences of the property division (504(a)(10))
Contributions and services of the party seeking maintenance to the education, training, career, or career potential of the other party (504(a)(11))
Any valid agreement of the parties (504(a)(12))
Any other factor the court expressly finds to be just and equitable (504(a)(13))
How Long Does Alimony Last?
While there is no universal rule, alimony duration in Illinois generally correlates with the length of the marriage:
| Marriage Length | Typical Alimony Duration |
|---|---|
| Under 5 years | 0-2 years |
| 5-10 years | 2-5 years |
| 10-20 years | 5-10 years |
| 20+ years | Indefinite / Permanent |
These are general guidelines. Actual duration depends on the specific facts of your case and the court's discretion.
Plan your financial future
Divorce.ai helps you understand potential alimony in your Illinois divorce so you can plan your finances with confidence.
When Does Alimony End?
Tax Implications of Alimony
Post-2018 Federal Tax Rules
For divorces finalized after December 31, 2018, the Tax Cuts and Jobs Act changed the tax treatment of alimony:
For the Payer
Alimony payments are not deductible from federal taxes.
For the Recipient
Alimony payments are not taxable income for federal taxes.
State tax treatment may differ. Consult a tax professional for advice specific to your situation.