Alimony · guide
How is alimony calculated?
Two methods coexist: a formula in a few states, and a judge weighing factors everywhere. Here is how each one turns two incomes into a monthly amount.
Checked by Radif Partners · Editorial policy · How we calculate
Alimony is calculated in one of two ways. In the states that publish a formula, the amount is a percentage of the higher earner's income minus a percentage of the lower earner's income, capped so that the recipient does not end up with more than a set share, often 40 percent, of the couple's combined income; for a higher earner at $8,000 a month and a spouse at $3,000, the formulas on this site give a median of about $1,440 a month. Everywhere else, and for final judgments in many formula states, the judge weighs statutory factors: the length of the marriage, each spouse's earning capacity and health, the standard of living, contributions to the household and the property each receives. Duration follows the length of the marriage in most states, through a fraction, a table or a maximum. Since 2019, new agreements are neither deductible nor taxable on federal returns.
Spousal support under the state formulas
California, a month
$1,700
| Income counted | net |
| A year | $20,400 |
| Rule | No statewide formula |
For a 12-year marriage without children; the judge decides eligibility first.
The formula method, step by step
Formula states start from each spouse's income, gross in some states and net in others. They take a percentage of the payer's income, subtract a percentage of the recipient's income, and compare the result with a ceiling. Illinois, for instance, takes a third of the payer's net income minus a quarter of the recipient's, then checks that the recipient's income plus maintenance does not exceed 40 percent of the couple's combined net income; the lower of the two figures is the guideline amount. New York uses 20 and 25 percent when child support is also paid, 30 and 20 percent when it is not, with the same 40 percent check and a cap on the payer income it applies to.
Three conditions often limit these formulas. Some apply only to temporary support while the divorce is pending. Some apply only below a combined income limit, above which the court decides freely. And some are advisory: the judge must compute them but may depart from them with written reasons.
The factor method
Most state statutes list what the court must consider rather than how to compute. The common factors are the length of the marriage; the age, health and earning capacity of each spouse; the time and cost of education or training to become self-supporting; the standard of living established during the marriage; contributions as a homemaker or to the other spouse's education and career; the property division; and the tax consequences. Some states add marital misconduct. A judge applying factors often starts from the recipient's reasonable needs and the payer's ability to pay, which is why budgets and financial affidavits matter so much in those states.
How long support lasts
Duration rules tie support to the length of the marriage, measured from the wedding to the filing or the separation depending on the state. Some use a fraction (half of the marriage as a guide in California for marriages under ten years), some a table of factors (Illinois multiplies the length of the marriage by a factor that rises with each year), some a maximum (Texas allows five, seven or ten years depending on the length of the marriage). Long marriages, often twenty years or more, may justify support for an indefinite period. Rehabilitative support, meant to pay for training or education, has a shorter, defined term.
Temporary, rehabilitative, permanent
Temporary or pendente lite support covers the period of the case itself. Rehabilitative support helps a spouse become self-supporting. Durational or general term support follows the marriage-length rules. Permanent alimony has been abolished or restricted in several states, Florida among them since 2023. Reimbursement alimony repays a spouse who supported the other through school.
Taxes and the order of calculation
Agreements executed after 2018 are tax-neutral at the federal level: the payer cannot deduct alimony and the recipient does not report it (IRS Topic 452). Older agreements keep their deductible treatment unless modified to adopt the new rule. When child support is also ordered, states differ on which comes first; the result can move the alimony figure by hundreds of dollars a month, which is why the full alimony calculator asks whether child support is paid.
A worked comparison
Take spouses married twelve years, one earning eight thousand dollars a month and the other three thousand, with no children. Under an Illinois-style formula, a third of the payer's net minus a quarter of the recipient's net gives the first figure, then the 40 percent ceiling on combined net income is checked. Under a Massachusetts-style rule, the amount falls in a range of 30 to 35 percent of the difference in gross incomes. Under a Texas-style rule, the court first decides whether the spouse is eligible at all, then cannot exceed the cap. Run the mini calculator above with the same incomes in different states and the results move by hundreds of dollars a month, before duration rules make the gap larger still. That spread is why spouses in formula states often settle near the guideline, while spouses elsewhere negotiate from budgets.
Imputed income and earning capacity
Formulas use income, but courts may substitute earning capacity. A spouse who quits a job or works far below his or her qualifications can be assigned the income he or she could reasonably earn, based on work history, education and the local job market. The same applies to a payer who reduces income to lower support. Expect to document job searches and offers if earning capacity is disputed.
Modifying or ending it
Periodic alimony usually ends at the recipient's remarriage or either spouse's death, and may be reduced when the recipient cohabits or when the payer's income falls substantially. Agreements can make support non-modifiable. Retirement can end or reduce support in states that tie it to full retirement age.