Illinois Alimony Calculator 2026
Every state calculates differently. Enter two incomes and a marriage length — see the monthly amount, how long it lasts, and the lifetime total, with the math shown step by step.
Your State
Incomes
Length of Marriage
From wedding date to separation — the single biggest driver of duration.
Case Factors discretion states
These adjust the estimate where judges have discretion.
Estimated alimony
Range $1,073 – $2,070 · Formula State in Illinois
How long it lasts
Expected duration
4 years
Lifetime total
$73,590
Conservative
$42,927
Guideline
$73,590
Aggressive
$113,834
Alimony is likely
The income gap and marriage length suggest spousal support is likely to be considered. The range above is your negotiation baseline.
The math, step by step
33.33% × $6,400 net − 25% × $2,400 net = $1,533/mo (cap 40% of combined net)
What if the marriage lasted longer?
Same incomes — only the length of marriage changes. Lifetime totals at each length:
5 yrs
$18,397
10 yrs
$73,590
15 yrs
$165,577
20 yrs
$294,359
Most likely type of award
📅Durational / Bridge-the-Gap
Time-limited support for a defined period — typically up to half the marriage length.
Educational estimate only — not legal advice. Alimony is highly fact-specific; judges deviate for misconduct, assets, and each family's circumstances. Post-2018 federal law made alimony neither taxable nor deductible. Consult a licensed family law attorney.
Alimony Calculators by State
Three different approaches, 51 rulebooks. Open your state for its formula, duration rules, and permanent-alimony stance.
How Alimony Works in Illinois
Formula State state. The math is written into statute: plug in both incomes and the guideline number falls out. Estimates here are the most reliable in these states. (33.33% × payer net) − (25% × receiver net). Cap: 40% of combined net.
Duration: Statutory: under 5 yrs = 20% of marriage; adds 4% per year after the 5th year — permanent alimony is not available in Illinois.
Worth knowing: Illinois abolished permanent alimony — a strong formula state.
Tax treatment: for agreements finalized after 2018, alimony is neither deductible by the payer nor taxable to the receiver in Illinois or anywhere else in the US.
Formula, Hybrid, or Discretion — Which Applies?
Which one applies to you depends entirely on your state.
7 states
The math is written into statute: plug in both incomes and the guideline number falls out. Estimates here are the most reliable in these states.
3 states
Courts start from a guideline formula but adjust for the circumstances of the case — the number is a strong starting point, not a guarantee.
41 states
No formula. Judges weigh need, ability to pay, marriage length, and the factors you toggle below. Treat estimates as a wide negotiation range.
Frequently Asked Questions
How is alimony calculated in Illinois?
How long does alimony last in Illinois?
Does Illinois award permanent alimony?
What bars or reduces alimony in Illinois?
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