Illinois Alimony Calculator

Estimate spousal support payments under Illinois's statutory formula. The state formula applies up to 33.33% of income, with an income cap of $500,000.

Illinois Formula-Based

Your Income

$
Total income before taxes per year
$
Take-home pay after taxes per month

Spouse's Income

$
Total income before taxes per year
$
Take-home pay after taxes per month
years
Number of years married
Do you have children?
Having children may affect the alimony formula in some states
Higher earner: You (auto-detected from income inputs)
Illinois has a statutory formula under 750 ILCS 5/504: 33.33% of payor's net income minus 25% of payee's net income, capped at 40% of combined net income. Duration is set by a statutory table based on marriage length.
You would pay your spouse $640/month in alimony
Estimated Monthly Alimony
$640
$7,680 per year | 12-year marriage in Illinois
Suggested Duration6 years, 3 months
Total Lifetime Cost$48,000
Formula Used33.33% of payor net - 25% of payee net, capped so total s...
Types AvailableTemporary, Fixed-term, Reviewable, Permanent, Indefinite
State-Specific Notes
  • Post-2018 TCJA: alimony is not tax-deductible for the payor and not taxable income for the payee (federal).
Disclaimer: This calculator provides estimates only and does not constitute legal advice. Family law varies significantly by jurisdiction. Results are based on general guidelines and may not reflect your specific circumstances. Laws in Illinois may differ from the general formulas used here. Always consult a qualified family law attorney for advice specific to your situation.

Illinois Alimony Laws

Illinois has a statutory formula under 750 ILCS 5/504: 33.33% of payor's net income minus 25% of payee's net income, capped at 40% of combined net income. Duration is set by a statutory table based on marriage length.

Illinois is one of the states that uses a statutory formula to calculate spousal support, providing more predictability in alimony outcomes. However, courts retain discretion to deviate from the formula when circumstances warrant it.

How Illinois Calculates Spousal Support

Formula: 33.33% of payor's net income minus 25% of payee's net income. Total support cannot exceed 40% of combined net income. Duration: marriages 0-5yr = 20% of length; 5-6yr = 24%; 6-7yr = 28%; 7-8yr = 32%; 8-9yr = 36%; 9-10yr = 40%; 10-11yr = 44%; 11-12yr = 48%; 12-13yr = 52%; 13-14yr = 56%; 14-15yr = 60%; 15-16yr = 64%; 16-17yr = 68%; 17-18yr = 72%; 18-19yr = 76%; 19-20yr = 80%; 20+yr = court discretion or permanent.

Income cap: $500,000 per year. Income above this cap is subject to court discretion.

Maximum percentage: 33.33% of the paying spouse's income.

While the formula provides a starting point, courts may adjust the amount based on factors such as the standard of living during the marriage, each spouse's financial resources, contributions to the marriage, and the requesting spouse's ability to become self-supporting.

Types of Alimony Available in Illinois

Illinois courts may award the following types of spousal support:

  • Temporary
  • Fixed Term
  • Reviewable
  • Permanent
  • Indefinite

The type of alimony awarded depends on the circumstances of the divorce, including the length of the marriage, the financial needs of the requesting spouse, and the purpose the support is intended to serve.

Illinois Alimony Duration Guidelines

Statutory table: duration ranges from 20% of marriage length (0-5 years) to 80% (19-20 years). Marriages over 20 years may receive permanent or indefinite maintenance.

Courts may modify the duration of alimony if there is a substantial change in circumstances, such as a significant increase or decrease in income, retirement, remarriage of the recipient spouse, or cohabitation with a new partner.

Frequently Asked Questions: Illinois Alimony

How is alimony calculated in Illinois?

Illinois uses a statutory formula: 33.33% of payor's net income minus 25% of payee's net income. Total support cannot exceed 40% of combined net income. Duration: marriages 0-5yr = 20% of length; 5-6yr = 24%; 6-7yr = 28%; 7-8yr = 32%; 8-9yr = 36%; 9-10yr = 40%; 10-11yr = 44%; 11-12yr = 48%; 12-13yr = 52%; 13-14yr = 56%; 14-15yr = 60%; 15-16yr = 64%; 16-17yr = 68%; 17-18yr = 72%; 18-19yr = 76%; 19-20yr = 80%; 20+yr = court discretion or permanent. Courts may deviate from the formula based on specific circumstances of the case.

How long does alimony last in Illinois?

Statutory table: duration ranges from 20% of marriage length (0-5 years) to 80% (19-20 years). Marriages over 20 years may receive permanent or indefinite maintenance. The actual duration depends on the specific facts of each case, and courts may adjust based on changed circumstances.

Can alimony be modified in Illinois?

Yes, in most cases alimony can be modified in Illinois if there is a substantial change in circumstances. Common grounds include significant changes in income, job loss, retirement, serious illness, or the recipient spouse becoming self-supporting. Some types of alimony, such as lump-sum awards, may not be modifiable.

Is alimony taxable in Illinois?

For divorce agreements executed after December 31, 2018, alimony is not taxable income for the recipient and not tax-deductible for the payer under federal tax law (per the Tax Cuts and Jobs Act). Illinois follows federal tax treatment. For pre-2019 agreements that have not been modified, the old rules may still apply.

Does Illinois have permanent alimony?

Yes, Illinois allows Permanent / Indefinite alimony. This is typically reserved for long-term marriages where the receiving spouse cannot become self-supporting. The types of alimony available in Illinois include: Temporary, Fixed Term, Reviewable, Permanent, Indefinite.

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This website provides estimates for informational purposes only. This is not legal advice. Consult a qualified family law attorney for guidance specific to your situation.