Alimony Calculator
Higher-earning spouse's total income before taxes
Higher-earning spouse's take-home pay after taxes
Lower-earning spouse's total income before taxes
Lower-earning spouse's take-home pay after taxes
Total years of marriage (decimals supported)
Results are estimates only. Alimony is determined by courts based on many individual factors. Consult a licensed family law attorney in your jurisdiction.
Enter Spouse Incomes to Estimate Alimony
Fill in the payor and payee incomes and the length of the marriage to see estimated monthly payments, duration, and a comparison across 10 state formulas.
How to Use This Calculator
Select Income Period
Choose whether you will enter incomes as monthly or annual figures. Monthly is typically easier if you know your paycheck amounts. The calculator automatically converts to the other period.
Enter Both Spouses' Incomes
Input the payor's (higher earner's) gross and net incomes and the payee's (lower earner's) gross and net incomes. Gross is before taxes; net is take-home pay. Both are needed because different state formulas use different income bases.
Enter Marriage Length
Type the number of years you were married. Decimals are supported (e.g., 7.5 years). This is critical because nearly all formulas tie alimony duration to how long you were married, and some formulas adjust the amount as well.
Review All Formula Results
The results panel shows estimates from all 10 formulas simultaneously — monthly payment, duration, and total cost. Use the comparison bar chart to see the spread between formulas, and the income donut chart to visualize each party's share of combined income after alimony payments.
Frequently Asked Questions
Which alimony formula should I use?
The formula that applies to you depends on the state where your divorce is filed. If you live in Illinois, a judge will follow the Illinois statutory guideline; in Texas, the Texas statutory cap applies. If your state is not listed or uses judicial discretion (like Pennsylvania or Virginia), the AAML formula is the most widely cited general-purpose guideline used by practitioners nationwide. Because most states have some discretion built in, looking at the full range of estimates — from the low to the high — gives you the best sense of what is negotiable. Always confirm the applicable formula with a family law attorney in your state.
What is the AAML formula for alimony?
The AAML (American Academy of Matrimonial Lawyers) formula calculates monthly alimony as 30% of the payor's gross annual income minus 20% of the payee's gross annual income, divided by 12. There is an income cap: the payee's total income after receiving alimony cannot exceed 40% of the combined gross income of both parties. Duration follows four brackets: marriages under 3 years use 30% of the marriage length; 3–10 years use 50%; 10–20 years use 75%; and marriages of 20 or more years may result in indefinite or permanent alimony. This formula is not law in any specific state but is widely used as a reasonable starting point.
How is alimony duration determined?
Alimony duration is almost always tied to the length of the marriage, though the exact rules vary by state. Short marriages (under 5 years) typically result in brief or no alimony. Mid-length marriages (5–15 years) usually result in rehabilitative alimony lasting a fraction of the marriage length — commonly 30% to 70%. Long marriages (15–20+ years) can result in long-term or even permanent alimony, especially when one spouse has been out of the workforce for many years. Illinois has one of the most precisely codified duration tables, specifying a multiplier for each year range. This calculator shows duration estimates for each formula so you can compare across jurisdictions.
Is alimony taxable income?
Under the Tax Cuts and Jobs Act (TCJA) signed in December 2017, alimony rules changed for divorce or separation agreements finalized after December 31, 2018. For these agreements, alimony payments are no longer deductible by the payor and are no longer included in the recipient's taxable income. For divorces finalized before January 1, 2019, the old rules apply: the payor can deduct alimony, and the recipient must include it as taxable income. This is a significant consideration when negotiating settlements, as the after-tax cost and benefit of alimony differ substantially depending on which tax regime applies. Always consult a tax professional alongside your family law attorney.
Can alimony be modified after the divorce?
Yes, in most states alimony can be modified if there is a substantial change in circumstances after the original award. Common grounds for modification include a significant increase or decrease in either party's income, the recipient remarrying or cohabitating with a new partner (which terminates alimony in many states), either party's retirement, or a serious health change affecting earning capacity. Some divorce agreements include automatic termination clauses tied to specific events. Courts require evidence of a material change, not just routine income fluctuations. Prenuptial or postnuptial agreements that address alimony can also limit modification rights. Review your specific state's statutes and your divorce decree for the exact standards.
What is the 40% income cap in alimony calculations?
The 40% income cap is a guard rail used by the AAML formula and the Illinois statutory guideline to prevent alimony from resulting in the recipient earning more than the payor. Specifically, after receiving alimony, the recipient's total income (their own income plus the alimony payment) cannot exceed 40% of the combined gross (AAML) or combined net (Illinois) income of both parties. This cap is enforced automatically in this calculator — if the formula result would push the recipient above 40%, the payment is reduced to the maximum allowed. Many other states use similar principles informally, even if not codified as a hard cap.