Estimate monthly spousal support and how long it might last, under four guideline formulas
⚖️ Not legal advice. Real awards depend on the judge, state statutes, and negotiated agreements. These formulas are educational starting points; talk to a family law attorney.
| State / Approach | Formula | Cap | Typical Duration |
|---|---|---|---|
| Common guideline (AAML-style) | 30% of payor gross minus 20% of payee gross | No fixed cap | Roughly 30% to 75% of the marriage length |
| Texas (statutory) | 20% of payor average gross monthly income | $5,000/mo | Up to 5, 7, or 10 years by marriage length |
| New York (no child support) | Lesser of 30% payor minus 20% payee, and 40% of combined minus payee income | Payor income counted up to about $228,000 (adjusts annually) | Advisory 15% to 50% of the marriage length |
| Illinois (statutory) | 33.3% of payor net minus 25% of payee net | Payee income plus maintenance held to 40% of combined net | Marriage years times a 0.20 to 0.80 factor |
| Most other states | Judicial discretion guided by statutory factors | Varies | Varies by judge and case |
Only a handful of states publish a true formula. Everywhere else, these numbers work as negotiation anchors rather than predictions.
| Years Married | Duration Factor | Years Married | Duration Factor |
|---|---|---|---|
| Under 5 | 0.20 | 12 | 0.52 |
| 5 | 0.24 | 13 | 0.56 |
| 6 | 0.28 | 14 | 0.60 |
| 7 | 0.32 | 15 | 0.64 |
| 8 | 0.36 | 16 | 0.68 |
| 9 | 0.40 | 17 | 0.72 |
| 10 | 0.44 | 18 | 0.76 |
| 11 | 0.48 | 19 | 0.80 |
| 20 or more | Court may order the length of the marriage, or an indefinite term | ||
Multiply the factor by the years married. A 12-year marriage gets 12 × 0.52, which is 6.24 years of maintenance.
Alimony (also called spousal support or maintenance) is money one spouse pays the other after a divorce, meant to soften the income gap the marriage leaves behind. This calculator estimates the monthly amount and duration from three inputs: each spouse's gross income and the length of the marriage.
Most states have no formula at all, so the default here is the common 30/20 guideline that many attorneys use as a starting point: 30% of the payer's gross income minus 20% of the recipient's. Three states with real published rules are included too. Texas applies a hard cap, the lesser of $5,000 a month or 20% of gross monthly income, and usually requires 10 years of marriage. New York takes the lesser of two calculations and only counts payor income up to a statutory cap near $228,000. Illinois works from net income, 33.3% of the payer's minus 25% of the recipient's, then trims the result so the recipient's income plus maintenance stays at 40% of the couple's combined net. Since Illinois uses after-tax figures, this tool approximates net as 73% of gross.
Enter both gross annual incomes and the years married, then switch between formulas to see how the same facts play out in different systems. The duration estimate follows each formula's own schedule, from Illinois's precise factor table to the loose multiplier ranges attorneys use with the 30/20 rule.
Take a payer earning $120,000, a recipient earning $40,000, and a 12-year marriage under the common guideline. The math: 30% of $120,000 is $36,000, minus 20% of $40,000, which is $8,000. That leaves $28,000 a year, or about $2,333 a month. For duration, a 10-to-20-year marriage typically supports alimony for around 75% of its length, so 9 years here. Paid in full, that totals $252,000, which is why even rough guideline numbers are worth knowing before anyone signs anything.
There's no national formula. Most states leave the amount to judges, who weigh incomes, marriage length, age, health, and earning capacity. Where guidelines exist, they're income percentages: the common 30/20 rule takes 30% of the payer's gross income minus 20% of the recipient's. On $120,000 and $40,000 incomes, that's about $2,333 a month.
Most states set no strict minimum, but length matters everywhere. Texas is the strictest mainstream example: court-ordered maintenance usually requires 10 years of marriage unless there's family violence or a disability. Shorter marriages produce shorter awards, and marriages past 20 years often support indefinite or long-term orders.
Not for agreements signed after December 31, 2018. Under federal law, the payer gets no deduction and the recipient reports no income. Older agreements keep the old treatment, deductible for the payer and taxable to the recipient, unless they're modified to adopt the new rules. A few states, including California, still differ on state returns.
Texas caps court-ordered spousal maintenance at the lesser of $5,000 a month or 20% of the payer's average gross monthly income. A payer grossing $10,000 a month tops out at $2,000. The $5,000 ceiling only binds once gross income passes $25,000 a month. Couples can agree to more by contract.
Usually, yes. Court-ordered support can be modified after a substantial change in circumstances, such as job loss, retirement, or disability, and it typically ends if the recipient remarries. Agreements can be made non-modifiable by contract, and lump-sum or property-based awards generally can't be changed.