Topic guide · updated 2026-08-03
Does your state have an alimony formula?
For most people the answer is no, and that is the single most useful thing to learn about spousal support. A few states compute a guideline amount, a few more cap it, and the rest publish a list of factors and leave the number to the court.
Search for an alimony calculator and every result will give you a number. Most of those numbers are fabricated — not maliciously, but structurally, because the site has applied a guideline to a state that never adopted one.
The honest starting question is not how much. It is whether your state publishes a way to work out how much at all. There are three answers, and which one applies to you changes what can be known before a lawyer is involved.
What follows is the shape of the law, not a prediction. Even in the states that do publish a formula, the result is presumptive: a court can depart from it, and says why when it does.
Three kinds of state
A small number of states compute a guideline amount by statute. Illinois takes a third of the payor's net income less a quarter of the payee's, then limits the result so the payee does not end up with more than forty per cent of the parties' combined net income. New York does something structurally similar on gross income, with two formulas rather than one. A few states publish no formula but do cap what a court may order. That is a real, computable number — a ceiling — and it is not the same thing as an estimate. Most states publish neither. The statute lists factors, the court weighs them, and no arithmetic exists. That is the honest answer for the majority of the country, and it is the answer this site gives.
What a guideline state actually computes
Both formula states work the same way in outline: a share of the higher earner's income, less a share of the lower earner's, subject to a limit expressed as a share of the parties' combined income. The limit is what stops the formula producing an absurd result when the incomes are far apart. The details are where they diverge, and the details matter. Illinois runs on net income, switches its guideline off entirely once combined gross income reaches five hundred thousand dollars, and switches it off again where the payor already owes support from a prior relationship. New York runs on gross income, applies the formula only to the payor's income up to a cap that is re-published every two years, and has two sets of percentages — the lower pair applying only where the payor is also the non-custodial parent paying child support to the payee. That last point is worth dwelling on, because it means a New York maintenance figure cannot be computed without knowing something about the children.
A ceiling is not an estimate
Texas publishes no formula, and its eligibility rules are strict enough that many spouses cannot receive maintenance at all. But it does cap the amount: a court may not require monthly payment of more than the lesser of five thousand dollars or twenty per cent of the obligor's average monthly gross income. Florida caps durational alimony at the obligee's reasonable need or thirty-five per cent of the difference between the parties' net incomes, whichever is less. The first half of that test is a finding of fact no calculator can make, so the computable half is a ceiling on a ceiling. Both are useful and both are law. Neither is a forecast. An award at the statutory maximum is the exception, not the expectation, and presenting a ceiling as an estimate would be the same error as presenting a borrowed guideline as a state's own.
Duration is published more often than amount
A state that tells you nothing about how much may still tell you a great deal about how long. Illinois multiplies the length of the marriage by a factor that rises year by year, from a fifth under five years to four fifths at nineteen; at twenty years the court chooses between a term equal to the marriage and an indefinite one. Florida caps the term as a share of the marriage, rising with the marriage class, and bars durational alimony outright after a marriage of under three years. Texas sets flat year ceilings by band, with open-ended exceptions where the recipient is disabled or caring for a disabled child. New York publishes a range and labels it advisory. California publishes something different again: not a limit but a goal, that the supported party become self-supporting within a reasonable period, which for a marriage under ten years generally means half the length of the marriage. It expressly does not restrict how long a court may order support to run.
Why the factors are the real content
In a factor state the checklist is not background reading — it is the law. A court that ignores a listed factor can be reversed for it, and the factors are also what a court reaches for when departing from a guideline in a state that has one. They are worth reading before a first consultation for a practical reason: they are what a lawyer will ask you about. The length of the marriage, each party's earning capacity and what impaired it, contributions to the other spouse's education or career, the standard of living established during the marriage, the age and health of both parties. Having documented answers to those is worth more than having a number.
Tools in this topic
Every calculator and explainer in this cluster, each built on verified figures with its official source linked.
Guides
Key terms
Frequently asked questions
Because most states do not publish one. Where a state's statute lists factors and sets no formula, any dollar figure has to come from somewhere else — usually a guideline borrowed from another state or from a bar-association proposal that was never adopted. Showing you the factors, the statutory ceiling if there is one, and the duration rule is everything that can honestly be said.
Official sources for this topic
Every figure and rule referenced above is published by one of these agencies, and each of them — not this site — determines what is actually paid.
Rule-change alerts — when a guideline, cap or statute we publish is re-verified
One email when the numbers change. Double opt-in, no spam, unsubscribe anytime.