Illinois Maintenance (Alimony) Calculator

What Is the Illinois Alimony Calculator?

The Illinois Alimony Calculator is an online tool that estimates:

• Monthly maintenance payments
• Annual maintenance payments
• Expected duration of payments

It does this by applying the state’s official formula to three key pieces of information:

1. Payor’s Gross Annual Income (the spouse paying support)
2. Recipient’s Gross Annual Income (the spouse receiving support)
3. Length of Marriage (in years)

If the couple’s combined gross income is $500,000 or more, the statutory guidelines don’t apply. In those cases, the judge has full discretion to decide what’s fair.

How Does the Illinois Maintenance Formula Work?

Here’s a breakdown of the formula used in the calculator:

1. Convert gross to net income
   Illinois law often bases alimony on net income. The calculator estimates this as 72% of gross income for both spouses.
   • Example: $120,000 gross → $86,400 net
2. Apply the statutory formula
   • 33⅓% of the payor’s net income
   • Minus 25% of the recipient’s net income
   That gives the guideline annual maintenance amount.
3. Check the cap
   The law caps support so the recipient doesn’t end up with more than 40% of the combined net income. The calculator automatically adjusts for this.
4. Divide by 12
   This gives the monthly payment estimate.

How Duration of Maintenance Is Calculated

In Illinois, the length of the marriage affects how long payments last. The law applies a duration factor (a percentage of marriage length).

For example:

• Married 5 years → Pay maintenance for 1.2 years (20–24%)
• Married 10 years → Pay maintenance for 4 years (40%)
• Married 15 years → Pay maintenance for about 9 years (60%)
• Married 20+ years → Courts may order maintenance equal to the marriage length or indefinite maintenance.

The calculator uses these duration factors to show you an estimated payment timeline.

Example Calculation

Let’s say:

• Payor’s gross annual income = $120,000
• Recipient’s gross annual income = $35,000
• Marriage length = 12 years

The calculator would show:

• Monthly Maintenance: Around $1,700
• Annual Maintenance: About $20,400
• Duration: Roughly 5.8 years

(These numbers are estimates. Courts may adjust based on circumstances.)

Why Use the Illinois Maintenance Calculator?

• Clarity: Divorce negotiations are stressful. Knowing what the law says helps set expectations.
• Fairness Check: See if proposed support lines up with statutory guidelines.
• Planning Tool: Useful for budgeting and financial planning during a divorce.

Remember, the calculator gives a guideline estimate only. Courts can deviate if special circumstances apply, such as:

• Health issues
• Child support obligations
• Property division
• Agreements between spouses

Important Disclaimer

This calculator is not legal advice. It’s based on Illinois law for couples earning under $500,000 combined.
Final decisions rest with the court. Always consult with a qualified Illinois family law attorney for personalized guidance.